Wireless chip

ABSTRACT

The invention provides a wireless chip which can secure the safety of consumers while being small in size, favorable in communication property, and inexpensive, and the invention also provides an application thereof. Further, the invention provides a wireless chip which can be recycled after being used for managing the manufacture, circulation, and retail. A wireless chip includes a layer including a semiconductor element, and an antenna. The antenna includes a first conductive layer, a second conductive layer, and a dielectric layer sandwiched between the first conductive layer and the second conductive layer, and has a spherical shape, an ovoid shape, an oval spherical shape like a go stone, an oval spherical shape like a rugby ball, or a disc shape, or has a cylindrical shape or a polygonal prism shape in which an outer edge portion thereof has a curved surface.

TECHNICAL FIELD

The invention relates to a wireless chip which communicates wirelesslythrough electromagnetic waves.

BACKGROUND ART

In recent years, an automatic recognition technique which is constitutedby a wireless chip which stores data in its electronic circuit, areader/writer which reads and writes data stored in the wireless chip,and a host system which processes the read data, controls thereader/writer, or the like has been developed and introduced (see FIGS.2A and 2B). A wireless chip 201 is called by various names such as anRFID tag, an IC tag, and a wireless tag, however, as a specific namedoes not exist, it is called a wireless chip in this specification. Thewireless chip 201 basically has no battery and performs a dielectricoperation by electromagnetic waves emitted from the reader/writer 202 towirelessly communicate with the reader/writer 202. Moreover, a computer203 is generally used as a host system which communicates with thereader/writer 202 through a serial port, an USB (Universal Serial Bus)port 204, or the like. This automatic recognition technique is expectedto be capable of totally managing the manufacture, circulation, andretail of objects. Therefore, a wireless chip which is inexpensive,favorable in communication property, and small in size has beendeveloped.

As an example, Patent Document 1 discloses a stacked-layer electroniccomponent which is small in size and superior in electroniccharacteristics by using a plurality of two or more kinds of resinsubstrates which have different dielectric constants and permeability.

-   Japanese Patent Document Laid-open No. 2004-6897

DISCLOSURE OF INVENTION

Other than the electronic components disclosed as examples in theaforementioned patent document, a small and inexpensive wireless chiphas been developed and an automatic recognition technique using thewireless chip has been introduced into the market. When these techniquesare used for the manufacture, circulation, and retail of objects, thewireless chip ultimately reaches a consumer. The ultimate consumers aregeneral public including people who have no knowledge about the wirelesschip and the automatic recognition technique. Therefore, for example,there is a risk of an unexpected accident such as injuring skin ordrinking by mistake. Moreover, there is a problem in the disposal methodand recycling since a large number of wireless chips are used when usedfor retail.

The invention provides a wireless chip which is small in size, favorablein communication property, and inexpensive and which can ensure thesafety of the ultimate consumer, and an application thereof.Furthermore, the invention provides a wireless chip which can berecycled after being used for managing the manufacture, circulation, andretail.

In order to solve the aforementioned objects, the invention provides thefollowing means.

A wireless chip of the invention includes an antenna and a layerincluding a semiconductor element electrically connected to the antenna.The antenna includes a first conductive layer, a second conductivelayer, and a dielectric layer sandwiched between the first conductivelayer and the second conductive layer. The dielectric layer has aspherical shape, an ovoid shape, an oval spherical shape like a gostone, an oval spherical shape like a rugby ball, a disc shape, or has acylindrical shape or a polygonal prism shape in which an outer edgeportion of the cylindrical shape or the polygonal prism shape has acurved surface.

In the aforementioned wireless chip, the antenna and the layer includinga semiconductor element are electrically connected through a resin layercontaining conductive particles.

A wireless chip of the invention includes a layer including asemiconductor element, a layer including a passive element electricallyconnected to the layer including the semiconductor element, and anantenna electrically connected to the layer including the passiveelement. The antenna includes a first conductive layer, a secondconductive layer, and a dielectric layer sandwiched between the firstconductive layer and the second conductive layer. The dielectric layerhas a spherical shape, an ovoid shape, an oval spherical shape like a gostone, an oval spherical shape like a rugby ball, a disc shape, or has acylindrical shape or a polygonal prism shape in which an outer edgeportion thereof has a curved surface.

In the aforementioned wireless chip, the layer including a passiveelement includes a passive element formed of at least one of aninductor, a capacitor, and a resistor. The layer including a passiveelement and the semiconductor element are electrically connected througha resin layer containing conductive particles.

Further, an antenna included in the wireless chip of the inventionincludes a first conductive layer which functions as an emitterelectrode, a second conductive layer which functions as a ground, and adielectric layer sandwiched between the first conductive layer and thesecond conductive layer.

Further, a layer including a semiconductor element in the wireless chipof the invention is formed over a semiconductor substrate or aninsulating substrate. The insulating substrate may be a flexiblesubstrate. Further, a semiconductor element formed over an insulatingsubstrate has an inorganic semiconductor layer or an organicsemiconductor layer. The thickness of the layer including asemiconductor element is preferably 1 to 5 μm.

Further, a wireless chip of the invention includes a high frequencycircuit.

In a wireless chip of the invention, a dielectric layer which forms anantenna is formed of one or a plurality selected from alumina, glass,forsterite, barium titanate, lead titanate, strontium titanate, leadzirconate, lithium niobate, and lead zirconate titanate. Further, thedielectric layer can also be formed of one or a plurality selected froman epoxy resin, a phenol resin, a poly butadiene resin, a BT resin,vinyl benzyl, and polyfumarate.

Coated with a resin or DLC, a wireless chip of the invention has aspherical shape, an ovoid shape, an oval spherical shape like a gostone, an oval spherical shape like a rugby ball, a disc shape, or has acylindrical shape or a polygonal prism shape in which an outer edgesurface thereof has a curved surface.

The invention can provide a wireless chip which is small in size,favorable in communication property, and inexpensive by forming anantenna using a dielectric with a high dielectric constant or a magneticbody.

Further, the invention can provide a wireless chip with high safetywhich does not cause an injury or the like when touched, by forming anouter shape of a dielectric layer which forms the outer shape of thewireless chip so as to have only a flat surface and a curved surface.

The invention can provide a wireless chip with high safety which doesnot harm a human body even when the wireless chip is drunk by mistake,by coating the outermost surface with a resin or DLC (Diamond-LikeCarbon) so as to have a shape with a curved surface. Moreover, thephysical strength of the wireless chip is enhanced by coating theoutermost surface thereof, which leads to a recyclable wireless chipwhich can be used repeatedly.

Furthermore, in the case of attaching a wireless tag to a product, awireless tag may be wrapped with paper, plastic, cloth, or the like orincorporated in a bag, a box, a free gift, or the like. Accordingly, thewireless chip can be safely used by forming the outermost surfacethereof with a material and a shape with high safety and a size and ashape that the consumers can easily recognize the wireless tag.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1A is a perpendicular view and 1B is a sectional view of awireless chip of the invention.

FIGS. 2A and 2B are block diagrams showing circuit configurations of awireless chip of the invention.

FIGS. 3A to 3D are views showing manufacturing steps of an antenna whichforms a wireless chip of the invention.

FIGS. 4A to 4C are sectional views of semiconductor elements which formsa wireless chip.

FIGS. 5A and 5B are views showing manufacturing steps of semiconductorelements and memory elements which form a wireless chip.

FIGS. 6A to 6C are views showing manufacturing steps of semiconductorelements and memory elements which form a wireless chip.

FIGS. 7A and 7B are sectional views of a wireless chip of the invention.

FIG. 8 is a sectional view of a semiconductor element which forms awireless chip of the invention.

FIGS. 9A and 9B are sectional views of semiconductor elements which forma wireless chip of the invention.

FIGS. 10A to 10C are diagrams showing wireless chips of the invention.

FIGS. 11A to 11C are views showing uses of a wireless chip of theinvention.

FIGS. 12A to 12D are views showing antennas which form a wireless chipof the invention.

FIGS. 13A to 13C are block diagrams showing circuit configurations of awireless chip of the invention.

FIG. 14 is a sectional view of a wireless chip of the invention.

FIG. 15A is a top plan view and FIGS. 15B and 15C are sectional views ofsemiconductor elements which form a wireless chip.

FIGS. 16A to 16D are sectional views showing manufacturing steps ofsemiconductor elements which form a wireless chip.

FIGS. 17A to 17C are sectional views showing manufacturing steps ofsemiconductor elements which form a wireless chip.

FIGS. 18A to 18D are sectional views showing manufacturing steps ofsemiconductor elements which form a wireless chip.

FIGS. 19A to 19D are sectional views showing manufacturing steps ofsemiconductor elements which form a wireless chip.

FIGS. 20A to 20D are sectional views showing manufacturing steps ofsemiconductor elements which form a wireless chip.

FIGS. 21A and 21B are sectional views showing manufacturing steps ofsemiconductor elements which form a wireless chip.

FIGS. 22A and 22B are sectional views showing manufacturing steps ofsemiconductor elements which form a wireless chip.

FIGS. 23A to 23G are diagrams showing shapes of an antenna which forms awireless chip.

BEST MODE FOR CARRYING OUT THE INVENTION Embodiment Mode

Although the invention will be fully described by way of embodimentmodes and embodiments with reference to the accompanying drawings, it isto be understood that various changes and modifications will be apparentto those skilled in the art. Therefore, unless such changes andmodifications depart from the scope of the invention, they should beconstrued as being included therein. Note that identical portions inembodiment modes are denoted by the same reference numerals in differentdrawings.

Embodiment Mode 1

As shown in FIG. 2A, the wireless chip 201 of the invention wirelesslycommunicates with the reader/writer 202. The wireless chip 201 generallyoperates by receiving power supply from the reader/writer 202 throughelectromagnetic waves for communication. Receiving the data transmittedfrom the reader/writer 202, the wireless chip 201 determines right orwrong thereof and sends back the stored data to the reader/write 202when the data is right. Furthermore, the wireless chip 201 stores anderases the data based on the instruction received from the reader/writer202.

FIGS. 1A and 1B show a wireless chip of the invention with theaforementioned configuration. FIG. 1A is a perspective view showing anexample of an appearance of the wireless chip and FIG. 1B is a sectionalview of the wireless chip.

As shown in FIG. 1A as an example, the wireless chip of the inventionhas a cylindrical shape and a curved surface in an outer edge portion.In specific, corners at which a top surface, a bottom surface, and aside surface of the cylindrical shape intersect are rounded off bygrinding or the like, thereby a shape having only a flat surface and acurved surface is obtained. Besides, a shape with no corner may beobtained by forming a polygonal prism shape such as a quadratic prismand rounding off corners at which a top surface, a bottom surface, and aside surface intersect and corners at which a side surface and anotherside surface intersect as shown in FIGS. 23A to 23C. Furthermore, aspherical shape, an ovoid shape (FIG. 23D), an oval spherical shape likea go stone (FIG. 23E), an oval spherical shape like a rugby ball (FIG.23F), a disc shape (FIG. 23G), or the like may be obtained.

Further, as shown in FIG. 1B, a wireless chip of the invention includesan antenna 101 and a layer 102 including a semiconductor element. Theantenna 101 is a plane antenna formed by sandwiching a dielectric layer106 between two conductive layers which are parallel to each other (afirst conductive layer 103 and a second conductive layer 104). Theantenna 101 transmits and receives electromagnetic waves so that thewireless chip wirelessly communicates with a reader/writer. The layerincluding a semiconductor element is formed of a plurality of circuitsincluding a transistor, a capacitor, a diode, or the like and performsprocessing, storing, or the like of the data received from thereader/writer.

FIG. 2B shows a circuit configuration example of a wireless chip of theinvention having the aforementioned function.

The wireless chip 201 of the invention includes an antenna 211, a layer212 including a semiconductor element, a communication circuit portion213, an arithmetic processing circuit portion 214, a power sourcecircuit portion 215, a memory portion 216, a demodulation circuit 217,and a modulation circuit 218. The antenna 211 and the layer 212including a semiconductor element are the same ones as the antenna 101and the layer 102 including a semiconductor element shown in FIG. 1B.

The antenna receives electromagnetic waves emitted from thereader/writer and generates an alternating dielectric voltage. Thedielectric voltage corresponds to a driving power of the wireless chip201 and contains data from the reader/writer 202.

A frequency band of the electromagnetic waves used for the wirelesscommunication between the reader/writer and the wireless chip is a longwaveband of 30 to 135 kHz, a short waveband of 6 to 60 MHz (typically13.56 MHz), an ultra-short waveband of 400 to 950 MHz, a microwave bandof 2 to 25 GHz, or the like. The antenna can be appropriately designedin accordance with the frequency of electromagnetic waves used for thecommunication. Further, an antenna for communicating with thereader/writer and an antenna for supplying the driving power can beseparately provided as well.

The layer 212 including a semiconductor element includes, for example,an arithmetic processing circuit portion, a memory, a communicationcircuit portion, a power source circuit portion, and the like.

The communication circuit portion includes a demodulation circuit and amodulation circuit. The demodulation circuit demodulates data receivedby the antenna from the reader/writer and outputs it to the arithmeticprocessing circuit portion. The modulation circuit modulates data storedin the memory and transmits it to the reader/writer. The arithmeticprocessing circuit portion performs operations such as determining thedemodulated data from the reader/writer right or wrong or reading thedata from the memory and outputting it to the modulation circuit.

The memory contains data specific to the wireless chip. Therefore, thememory includes a write once type nonvolatile memory, a rewritablenonvolatile memory, a volatile memory, or the like. The power sourcecircuit portion generates a constant voltage from a dielectric voltagegenerated at the antenna and supplies the constant voltage as a drivingvoltage to each circuit. Further, the power source circuit portion mayhave a clock generating circuit or the like for generating a clocksignal with a frequency required for other circuits.

Next, description is made on a manufacturing method of a wireless chipof the invention in the order from a method for forming an antenna, amethod for forming a layer including a semiconductor element, and amethod for connecting the antenna and the layer including asemiconductor element.

As shown in FIG. 1B, the antenna 101 which forms the wireless chip isformed larger and thicker than the layer 102 including a semiconductorelement. The shape of a wireless chip of the invention is almostdetermined by the antenna 101. The antenna 101 has a structure in whichthe dielectric layer 106 is sandwiched between the first conductivelayer 103 and the second conductive layer 104. The dielectric layer 106almost determines the shape of the antenna 101. Therefore, the shape ofa wireless chip of the invention can be determined by forming thedielectric layer 106 into a cylindrical shape in which outer edgeportions thereof have curved surfaces as described above.

Further, the antenna 101 is formed by sandwiching the dielectric layer106 between the first conductive layer 103 which functions as an emitterelectrode and the second conductive layer 104 which functions as aground. Power may be fed from the first conductive layer 103 to thelayer including a semiconductor element by providing a power feedinglayer 105. Furthermore, a power feeding point may be provided to feedpower. In this embodiment mode, description is made on the antenna 101having a structure with the power feeding layer 105.

In the antenna 101, the dielectric layer 106 is formed using adielectric, a magnetic body, or the like and the conductive layers 103and 104 are formed using a conductive substance over a surface of thedielectric layer.

As a method for forming the dielectric layer 106, as shown in FIG. 3A, adielectric layer 301 in a cylindrical shape is formed (In the invention,the shape is not limited to a cylindrical shape and a polygonal prismshape can also be employed). As shown in FIG. 3B, by rounding offcorners at which a top surface, a bottom surface, and a side surfaceintersect by grinding or the like, a dielectric layer 302 in acylindrical shape in which outer edge portions thereof have curvedsurfaces is formed.

However, a dielectric layer of an antenna which forms a wireless chip ofthe invention is not limited to be formed by the aforementionedmanufacturing method, and can also be formed into a cylindrical shapehaving in which outer edge portions thereof have curved surfaces byusing a casting mold or the like. Furthermore, the dielectric layer maybe formed into a spherical shape, an ovoid shape, an oval sphericalshape like a go stone, an oval spherical shape like a rugby ball, a discshape, or the like.

The dielectric layer 106 is formed by using ceramic with a highdielectric constant, an organic resin, a mixture thereof, or the like.As typical examples of ceramic, silica, alumina, zirconia, glass,forsterite, and the like are given. Besides, titanium bariumneodymium-based ceramics, titanium barium tin-based ceramics, leadcalcium-based ceramics, titanium dioxide-based ceramics, bariumtitanate-based ceramics, lead titanate-based ceramics, strontiumtitanate-based ceramics, calcium titanate-based ceramics, titanic acidbismuth-based ceramics, titanic acid magnesium-based ceramics, and thelike are given. These materials may be used alone of in combination. Itis to be noted that titanium dioxide-based ceramics corresponds to theone in which a crystal structure of titanium dioxide is held, includingnot only the one containing only titanium dioxide but also the onecontaining a small amount of other additives. Further, other ceramicsmay similarly contain a small amount of other additives.

As an organic resin, a thermosetting resin or a thermoplastic resin canbe used. As examples of a thermosetting resin, an epoxy resin, a phenolresin, an unsaturated polyester resin, a vinyl ester resin, a polyimideresin, a polyphenylene ether resin, a bismaleimide-triazine resin, apolyfumarate resin, a polybutadiene resin, a polyvinyl benzyl ethercompound resin, and the like are given. As examples of a thermoplasticresin, resin materials such as liquid crystal polymer, an aromaticpolyester resin, a polyphenylene sulfide resin, a polyethyleneterephthalate resin, a polybutylene telephthalate resin, a BT resin, avinyl benzyl resin, a fluoroplastic resin, or the like can be given.Further, a plurality of organic resin materials may be mixed to be used.

In the case where the dielectric layer 106 is formed of a mixture ofceramic and an organic resin, it is preferable to disperse ceramicparticles in the organic resin. At this time, it is preferable that theceramic be contained in the dielectric layer by 20 to 60 volume %.Further, a particle size of ceramic is preferably 1 to 50 μm. Moreover,it is preferable that the dielectric constant of the dielectric layer106 be 2.6 to 150, and more preferably 2.6 to 40. By using aferroelectric material with a high dielectric constant, a volume of anantenna can be made small.

The dielectric layer 106 which forms the antenna is not limited to beformed of the ceramic and organic resins described above, but can beformed of a material selected for the purpose in consideration of aforming property, a workability, an adhesion property, and the like.

Next, as shown in FIG. 3C, the two conductive layers 103 and 104, andthe power feeding layer 105 are formed over the surface of thedielectric layer 302 which has a cylindrical shape in which outer edgeportions thereof have curved surfaces.

The two conductive layers 103 and 104 and the power feeding layer 105can be formed over the surface of the dielectric layer 302 using aconductive substance by a printing method, a plating method, or thelike.

Further, the two conductive layers 103 and 104 and the power feedinglayer 105 can be formed by forming a conductive layer over the entiresurface of the dielectric layer 302 by an evaporation method, asputtering method, or the like and processing the conductive layer intoa desired shape by etching.

As examples of conductive substances as materials of the two conductivelayers 103 and 104, and the power feeding layer 105, a metal such asgold, silver, copper, palladium, platinum, and aluminum, an alloythereof, or the like can be used.

The second conductive layer 104 and the power feeding layer 105 formedas described above are electrically connected to the layer 102 includinga semiconductor element. In specific, the second conductive layer 104 isconnected to a portion of the layer including a semiconductor element,where a ground potential is applied, and the power feeding layer 105 isconnected to the power source circuit portion, the communication circuitportion, and the like described with reference to FIG. 2B. Therefore,the aforementioned antenna preferably has a shape which can be easilyconnected to the layer 102 including a semiconductor element.

Further, it is preferable that the size of the antenna be severalmm×several mm to several tens mm×several tens mm. Typically, the size isabout 7×7 mm to 12×12 mm. Moreover, the thickness of the antenna isabout 1 to 15 mm, and typically 1.5 to 5 mm. The size of the antennadetermines the size of the wireless chip.

Next, description is made on a manufacturing method of a layer includinga semiconductor element.

The layer including a semiconductor element, which forms a wireless chipof the invention includes a plurality of circuits formed ofsemiconductor elements and a memory formed of a semiconductor elementand a memory element. Therefore, in this embodiment mode, description ismade on a manufacturing method of a semiconductor element and a memoryelement.

Here, in order to form a layer including a thin and small semiconductorelement which can be attached to the antenna formed as described above,description is made on a method for forming a semiconductor elementformed using a thin semiconductor film and an organic memory including amemory element using an organic compound.

An organic memory has a structure in which a layer containing an organiccompound or a mixed layer of an organic compound and an inorganiccompound is sandwiched between a pair of conductive layers. A decoder orthe like which forms a memory may be formed by a known technique.Further, a memory cell which forms a memory is formed of only the memoryelement or a transistor and the memory element. In this specification,the layer containing an organic compound or the mixed layer of anorganic compound and an inorganic compound are collectively referred toas an organic compound layer.

An organic compound layer included in a memory element is formed using asubstance of which crystalline state, conductive property, or the likechanges when light, heat, or an electrical effect is applied. A memoryelement with this structure stores a binary value state depending on astate where the organic compound layer is changed by the aforementionedlight, heat, or an electrical effect or a state with no effect to causea change. This memory element having a simple structure can be easilyformed thin.

First, a peeling layer 402 is formed over an insulating substrate 401(see FIG. 4A). The insulating substrate 401 can be formed of a substrateformed of glass, quartz, silicon, a metal, or the like. The peelinglayer 402 is formed by forming an element or a compound such as a metaland silicon over the entire surface or a part of the substrate. It is tobe noted in this embodiment mode that the peeling layer 402 is formed topeel off the layer including a semiconductor element formed over theinsulating substrate 401 and attaching it to an antenna. However, in thecase where the layer including a semiconductor element formed over theinsulating substrate 401 is attached to an antenna together with theinsulating substrate 401, the peeling layer 402 is not required to beformed. Next, an insulating layer 403 is formed so as to cover thepeeling layer 402. The insulating layer 403 is formed of silicon oxide,silicon nitride, or the like. Next, a semiconductor layer 404 is formedover the insulating layer 403 and crystallized by laser crystallization,thermal crystallization using a metal catalyst, or the like, and thenprocessed into a desired shape. Next, a gate insulating layer 405 isformed so as to cover the semiconductor layer. The gate insulating layer405 is formed of silicon oxide, silicon nitride, or the like. As thegate insulating layer 405, an insulating layer with a thin thickness anda high insulating property can be formed by deposition using a highdensity plasma CVD apparatus.

Next, a gate electrode layer 406 is formed. The gate electrode layer 406is formed of a conductive layer using a conductive element or compoundand processed into a desired shape. In the case of processing the layerby a photolithography method, a resist mask may be etched by plasma orthe like, thereby the width of a gate electrode can be formed narrow andthe performance of a transistor can be enhanced. FIG. 4A shows the casewhere the gate electrode layer is formed to have a stacked-layerstructure. Next, an n-type impurity region 407 and a p-type impurityregion 408 are formed by adding impurity elements to the semiconductorlayer 404. The impurity region is formed by forming a resist mask by aphotolithography method and adding impurity elements such as phosphorus,arsenic, boron, or the like thereto. Subsequently, an insulating layeris formed of nitrogen compound or the like and anisotropic etching in aperpendicular direction is applied to the insulating layer, thereby aninsulating layer 409 (sidewall) in contact with a side surface of thegate electrode is formed (see FIG. 4B). Subsequently, impurities areadded to the semiconductor layer including the n-type impurity region,thereby a first n-type impurity region 410 right under the sidewall 409and a second n-type impurity region 411 having a higher impurityconcentration than that of the first n-type impurity region 410 areformed. By the aforementioned steps, an n-type transistor 412 and ap-type transistor 413 are formed.

Next, an insulating layer 414 is formed so as to cover the transistors412 and 413 (see FIG. 4C). The insulating layer 414 is formed of aninorganic compound, an organic compound, or the like having aninsulating property. In FIG. 4C, the insulating layer 414 is formed tohave a stacked-layer structure. Next, contact holes to expose the secondn-type impurity region 411 and the p-type impurity region 408 are formedand a conductive layer 415 is formed to fill the contact holes andprocessed into a desired shape. The conductive layer 415 is formed of ametal element, a compound, or the like having a conductive property.Next, an insulating layer 416 is formed so as to cover the conductivelayer 415. The insulating layer 416 is formed of an inorganic compound,an organic compound, or the like having an insulating property.

Next, FIG. 5A shows the formation of a memory element. First, a contacthole to expose the conductive layer 415 is formed and a first conductivelayer 417 is formed so as to fill the contact hole. The first conductivelayer 417 is formed of a metal element, a compound, or the like having aconductive property, thereby a first conductive layer which constitutesa memory element is formed. The insulating layer 418 is formed of aninorganic compound, an organic compound, or the like having a highinsulating property in order to electrically isolate adjacent memoryelements. Subsequently, a contact hole to expose the first conductivelayer 417 is formed. Then, a wire 419 is formed over the firstconductive layer 417 to connect an antenna. Next, an organic compoundlayer 420 is formed to be in contact with the first conductive layer417, and then a conductive layer 421 is formed. The organic compoundlayer 420 is formed of an organic compound of which electricalcharacteristics change when an electrical effect is applied. Theconductive layer 421 is formed of a metal element, a compound, or thelike having a conductive property and functions as a second conductivelayer which constitutes the memory element. Next, a protective layer 422is formed. The protective layer 422 is formed of a compound, a resin, orthe like having an insulating property.

FIG. 5B shows a memory element with a different structure than theaforementioned memory element. In the memory element, the conductivelayer 415 formed to connect the transistor and the memory element inFIG. 4C is used as the first conductive layer of the memory element.First, contact holes to expose the second n-type impurity region 411 andthe p-type impurity region 408 are formed and a conductive layer 415 isformed to fill the contact holes and processed into a desired shape. Theconductive layer 415 functions as a first conductive layer whichconstitutes the memory element. Next, an organic compound layer 420 isformed so as to contact with the conductive layer 415, and then theconductive layer 421 is formed. The organic compound layer 420 is formedof an organic compound of which electrical characteristics change whenan electrical effect is applied. The conductive layer 421 is formed of ametal element, a compound, or the like having a conductive property andfunctions as a second conductive layer which constitutes the memoryelement. Next, the protective layer 422 is formed. The protective layer422 is formed of a compound, a resin, or the like having an insulatingproperty. In this manner, by forming the memory element in the contacthole, a small and thin semiconductor device can be formed. Moreover, asthe first conductive layer 417 and the insulating layer 418 are notrequired, the manufacturing steps can be reduced and a memory at lowercost can be provided.

Each of an insulating layer, a conductive layer, and an element can beformed of a single layer structure of a single material or astacked-layer structure of a plurality of materials.

The semiconductor layer including a semiconductor element, which isformed by the aforementioned steps may use any one of an amorphoussemiconductor, a microcrystal semiconductor, a polycrystalsemiconductor, an organic semiconductor, and the like. In order toobtain a semiconductor element with favorable characteristics, acrystalline semiconductor layer (low temperature polysilicon layer)crystallized at 200 to 600° C. (preferably 350 to 500° C.) or acrystalline semiconductor layer (high temperature polysilicon layer)crystallized at 600° C. or higher can be used. In order to obtain asemiconductor element with further favorable characteristics, asemiconductor layer crystallized using a metal element as a catalyst ora semiconductor layer crystallized by a laser irradiation method may beused. Moreover, a semiconductor layer formed by a plasma CVD methodusing a mixture gas of SiH₄ and F₂, a mixture gas of SiH₄ and H₂, or thelike or thus formed the semiconductor layer irradiated with laser may beused. A semiconductor layer of a semiconductor element in a circuit ispreferably formed to have a crystal boundary which extends in parallelto a direction of a carrier flow (a channel length direction). Such anactive layer can be formed by a continuous wave laser (can beabbreviated to CWLC) or a pulsed laser which operates at 10 MHz orhigher, or preferably 60 to 100 MHz. Moreover, the thickness of thesemiconductor layer is preferably 20 to 200 nm, and more preferably 50to 150 nm. By adding a hydrogen or halogen element to the semiconductorlayer (in particular, a channel forming region) at a concentration of1×10¹⁹ to 1×10²² atoms/cm³ or preferably at a concentration of 1×10¹⁹ to5×10²⁰ atoms/cm³, an active layer which has few defects and hardlycracks can be obtained.

A transistor formed as described above has an S value (sub-thresholdvalue) of 0.35 V/dec or lower and more preferably 0.09 to 0.25 V/dec.The mobility is preferably 10 cm²/Vs or higher. Further, the transistorpreferably has characteristics of 1 MHz or higher and more preferably 10MHz or higher by a ring oscillator which operates with a power sourcevoltage of 3 to 5 V. The transistor described in this embodiment modehas a structure in which a semiconductor layer, a gate insulating layer,and a gate electrode layer are sequentially stacked over a substrate,however, the invention is not limited to this example. For example, astructure in which a gate electrode layer, an insulating film, and asemiconductor layer are sequentially stacked may be employed as well.Further, in this embodiment mode, an n-type transistor has a firstn-type impurity region and a second n-type impurity region, however, theinvention is not limited to this and the impurity regions may have thesame impurity concentrations.

A material of which quality or condition changes by an electricaleffect, an optical effect, a thermal effect, or the like is used as amaterial for the organic compound layer. For example, a material havingan organic compound of which quality or condition changes when a voltageis applied, so that a first conductive layer and a second conductivelayer which constitute a memory element are short-circuited is used.Therefore, the thickness of the organic compound layer is set 5 to 100nm, and more preferably 10 to 60 nm. Such an organic compound layer canbe formed of an inorganic material or an organic material as follows byan evaporation method, a spin coating method, a droplet dischargemethod, or the like.

As a material for the organic compound layer, for example, an aromaticamine-based compound (that is, having a benzene ring-nitrogen bond) suchas 4,4′-bis[N-(1-naphthyl)-N-phenyl-ammo]-biphenyl (abbreviated toα-NPD), 4,4′-bis[N-(3-methylphenyl)-N-phenyl-amino]-biphenyl(abbreviated to TPD), 4,4′,4″-tris(N,N-diphenyl-amino)-triphenylamine(abbreviated to TDATA),4,4′,4″-tris[N-(3-methylphenyl)-N-phenyl-amino]-triphenylamine(abbreviated to MTDATA), and4,4′-bis[N-(4-(N,N-di-m-tolylamino)phenyl-N-phenylamino]biphenyl(abbreviated to DNTPD), polyvinyl carbazole (abbreviated to PVK), aphthalocyanine compound such as phthalocyanine (abbreviated to H₂Pc),copper phthalocyanine (abbreviated to CuPc), or vanadyl phthalocyanine(abbreviated to VOPc), or the like can be used. These materials have ahigh hole transporting property.

Besides, a material formed of a metal complex or the like having aquinoline skeleton or a benzoquinoline skeleton such astris(8-quinolinolato)aluminum (abbreviated to Alq₃),tris(4-methyl-8-quinolinolato)aluminum (abbreviated to Almq₃),bis(10-hydroxybenzo[h]-quinolinato)beryllium (abbreviated to BeBq₂), orbis(2-methyl-8-quinolinolato)-4-phenylphenolato-aluminum (abbreviated toBAlq), a metal complex having a oxazole-based or thiazole-based ligandsuch as bis[2-(2-hydroxyphenyl)-benzoxazolate]zinc (abbreviated toZn(BOX)₂), or bis[2-(2-hydroxyphenyl)benzothiazolate]zinc (abbreviatedto Zn(BTZ)₂), and the like can be used. These materials have a highelectron transporting property.

Other than the metal complexes, in addition, there are2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (abbreviated toPBD), 1,3-bis[5-(p-tert-butylphenyl)-1,3,4-oxadiazole-2-yl]benzene(abbreviated to OXD-7),3-(4-tert-butylphenyl)-4-phenyl-5-(4-biphenylyl)-1,2,4-triazole(abbreviated to TAZ),3-(4-tert-butylphenyl)-4-(4-ethylphenyl)-5-(4-biphenylyl)-1,2,4-triazole(abbreviated to p-EtTAZ), bathophenanthroline (abbreviated to BPhen),bathocuproin (abbreviated to BCP), and the like.

The organic compound layer may have a single layer structure or astacked-layer structure. In the case of a stacked-layer structure, theaforementioned materials can be selected to form a stacked-layerstructure. Further, the aforementioned organic compound material and alight emitting material may be stacked. As a light emitting material,4-dicyanomethylene-2-methyl-6-[2-(1,1,7,7-tetramethyljulolidin-9-yl)ethenyl]-4H-pyran(abbreviated to DCJT),4-dicyanomethylene-2-t-butyl-6-[2-(1,1,7,7-tetramethyljulolidin-9-yl)ethenyl]-4H-pyran,periflanthene,2,5-dicyano-1,4-bis[(10-methoxy-1,1,7,7-tetramethyljulolidin-9-yl)ethenyl]benzene,N,N′-dimethylquinacridone (abbreviated to DMQd), coumarin 6, coumarin545T, tris(8-quinolinolato) aluminum (abbreviated to Alq₃),9,9′-bianthlyl, 9,10-diphenylanthracene (abbreviated to DPA),9,10-bis(2-naphthyl) anthracene (abbreviated to DNA),2,5,8,11-tetra-t-buthylperylene (abbreviated to TBP), and the like aregiven.

A layer in which the above light-emitting material is dispersed may beused. In the layer in which the above light-emitting material isdispersed, an anthracene derivative such as9,10-di(2-naphthyl)-2-tert-butylanthracene (abbreviated to t-BuDNA), acarbazole derivative such as 4,4′-di(N-carbazolyl) biphenyl (abbreviatedto CBP), a metal complex such as bis[2-(2′-hydroxyphenyl)pyridinato]zinc(abbreviated to Znpp₂) or bis[2-(2′-hydroxyphenyl)benzoxazolate]zinc(abbreviated to ZnBOX), or the like can be used as a host material. Inaddition, tris(8-quinolinolato)aluminum (abbreviated to Alq₃),9,10-bis(2-naphthyl) anthracene (abbreviated to DNA),bis(2-methyl-8-quinolinolato)-4-phenylphenolate-aluminum (abbreviated toBAlq), or the like can be used.

Such an organic compound material changes its quality by a thermaleffect, or the like, therefore, a glass transition temperature (Tg) ispreferably 50 to 300° C., and more preferably 80 to 120° C.

In addition, a material in which metal oxide is mixed with an organiccompound material or a light-emitting material may be used. Note thatthe material in which metal oxide is mixed includes a state in whichmetal oxide is mixed or stacked with the above organic compound materialor the above light-emitting material. Specifically, it indicates a statewhich is formed by a co-evaporation method using multiple evaporationsources. Such a material can be referred to as an organic-inorganiccomposite material.

For example, in the case of mixing a substance having a high holetransporting property with a metal oxide, it is preferable to usevanadium oxide, molybdenum oxide, niobium oxide, rhenium oxide, tungstenoxide, ruthenium oxide, titanium oxide, chromium oxide, zirconium oxide,hafnium oxide, and tantalum oxide as the metal oxide.

In the case of mixing a substance having a high electron transportingproperty with a metal oxide, lithium oxide, calcium oxide, sodium oxide,potassium oxide, or magnesium oxide is preferably used as the metaloxide.

A material which is changed in its property by an electrical effect, anoptical effect, or a thermal effect can be used for the organic compoundlayer; therefore, for example, a conjugated polymer doped with acompound (photoacid generator) which generates acid by absorbing lightcan also be used. Here, as the conjugated polymer, polyacetylenes,polyphenylene vinylenes, polythiophenes, poly anilines, polyphenyleneethinylenes, or the like can be used. As the photoacid generator, arylsulfonium salt, aryl iodonium salt, o-nitrobenzyl tosylate, arylsulfonic acid p-nitrobenzyl ester, sulfonyl acetophenones, Fe-arenecomplex PF₆ salt, or the like can be used.

The first conductive layer and the second conductive layer whichconstitute a memory element can be formed of a conductive material. Forexample, a film formed of an element selected from aluminum (Al),titanium (Ti), molybdenum (Mo), tungsten (W), and silicon (Si), or analloy film using these elements thereof can be used. Moreover, a lighttransmissive material such as indium tin oxide (ITO), indium tin oxidecontaining silicon oxide, and indium oxide containing zinc oxide can beused. Further, silicon oxide or silicon nitride can be used for aninorganic material as a material for the protective layer 422. As anorganic material, polyimide, acrylic, polyamide, polyimide amide,resist, benzocyclobutene, siloxane, or polysilazane can be used. It isto be noted that a siloxane resin corresponds to a resin containing aSi—O—Si bond. Siloxane has a skeleton structure formed of a bond ofsilicon (Si) and oxygen (O). As a substituent, an organic groupcontaining at least hydrogen (for example, alkyl group and aromatichydrocarbon) is used. As a substituent, a fluoro group may be used.Alternatively, an organic group containing at least hydrogen and afluoro group may be used as a substituent. Polysilazane is formed of apolymer material having a bond of silicon (Si) and nitrogen (N) as astart material. By forming a protective layer using these materials,planarity can be enhanced and impurities can be prevented from entering.

A semiconductor element and a memory element may be provided for aplurality of layers. In the case of a multi-layer structure, it ispreferable to use a low dielectric constant material as a material foran interlayer insulating film in order to reduce the parasiticcapacitance between the layers. For example, a resin material such as anepoxy resin and an acrylic resin, a compound material formed of apolymer such as a siloxane-based polymer, and the like are given. Whenthe parasitic capacitance is reduced in the multi-layer structure, smallsize, high rate operation, and low power consumption can be realized. Byproviding a protective layer for preventing contamination of an alkalimetal, reliability can be improved. The protective layer is preferablyprovided so that an inorganic material such as aluminum nitride and asilicon nitride film wraps around the semiconductor element in thecircuit or the whole circuit.

Next, description is made on a method for peeling the semiconductorelement and the memory element formed as described above from theinsulating substrate 401 and attaching it to the antenna.

First, an aperture 427 is formed so as to expose the peeling layer 402and etchant is introduced therein, thereby the peeling layer 402 ispartially removed (see FIG. 6A). Next, a first flexible substrate 429(for example, a plastic film) is adhered from a direction of the topsurface of the insulating substrate 401. Then, a layer 428 including asemiconductor element and a memory element is peeled off from theinsulating substrate 401. In this manner, the layer 428 including asemiconductor element and a memory element can be transferred to thefirst flexible substrate 429 side. At this time, a material of thepeeling layer may remain on the layer including a semiconductor elementand a memory element. Subsequently, a second flexible substrate 430 (forexample, a thin plastic film) is adhered to the side of the layer 428including a semiconductor element and a memory element, which was incontact with the insulating substrate 401 (see FIG. 6B). By removing thefirst flexible substrate 429, the wire 419 to be connected to theantenna is exposed (see FIG. 6C).

At this time, it is preferable that the thickness of the layer 428including a semiconductor layer and a memory element be 5 μm or thinner,or more preferably 1 to 3 μm. Moreover, in the case of attaching a layerincluding a semiconductor element to an antenna having a curved surface,the semiconductor element can be less affected when a direction of acarrier flow of the semiconductor element (the channel length direction)is set to be parallel to a tangential line to the curved surface, inwhich an angle between the curved surface and the tangential line at theportion to which the semiconductor element is attached is minimized.

The layer including a semiconductor element, which is formed over thesecond flexible substrate 430 corresponds to the layer 102 including asemiconductor element shown in FIG. 1B.

Next, as shown in FIG. 3D, the antenna 101 formed by the aforementionedsteps and the layer 102 including a semiconductor element are attachedto each other so as to be electrically connected. It is preferable touse an anisotropic conductive adhesive for the attachment. In specific,attachment is carried out so that the second conductive layer 104 of theantenna is connected to a portion of the layer including a semiconductorelement, to which a ground potential is applied, and the power feedinglayer 105 is connected to the power source circuit portion, thecommunication circuit portion, or the like described with reference toFIG. 2B.

The invention can provide a wireless chip which is small in size,favorable in communication property, and inexpensive. Further, awireless chip of the invention has a cylindrical shape in which outeredge portions thereof have curved surfaces. In specific, a corner atwhich a top surface, a bottom surface, and a side surface of thecylindrical shape intersect is rounded off by grinding or the like,thereby a shape having only a flat surface and a curved surface isobtained. Besides, a shape with no corner may be obtained by forming apolygonal prism shape such as a quadratic prism and rounding off cornersat which a top surface, a bottom surface, and side surfaces intersectand corners at which side surfaces intersect. Furthermore, a sphericalshape, an ovoid shape, an oval spherical shape like a go stone, an ovalspherical shape like a rugby ball, a disc shape, or the like may beobtained, thereby a wireless chip can be provided with high safety whichdoes not cause an injury or the like when touched.

Embodiment Mode 2

In this embodiment mode, description is made on a differentmanufacturing method of the wireless chip of the invention with thefunction described in Embodiment Mode 1.

As shown in FIG. 7A, a wireless chip of this embodiment mode includes alayer 701 including a semiconductor element and an antenna 703. Thelayer 701 including a semiconductor element has a semiconductor elementsuch as a field effect transistor over a semiconductor substrate formedof silicon or the like. Moreover, the antenna may be similar to theantenna described in Embodiment Mode 1.

In the wireless chip of this embodiment mode, the antenna 703 and thelayer 701 including a semiconductor element are connected throughconductive layers 702 a and 702 b. In specific, a connecting terminal704 a formed over the surface of the layer 701 including a semiconductorelement is connected to a power feeding layer 713 of the antenna throughthe conductive layer 702 a. Then, a connecting terminal 704 b formedover the surface of the layer 701 including a semiconductor element andthe conductive layer 712 which functions as a ground of the antenna areconnected through the conductive layer 702 b. Moreover, a connectionportion between the antenna 703 and the layer 701 including asemiconductor element may be filled with an under-fill material 704 aswell.

The antenna 703 includes a dielectric layer 710, two conductive layers(a first conductive layer 711 and the second conductive layer 712) andthe power feeding layer 713. The dielectric layer 710 has a cylindricalshape in which outer edge portions thereof have curved surfacessimilarly to Embodiment Mode 1. In specific, corners at which a topsurface, a bottom surface, and a side surface of the cylindrical shapeintersect are rounded off by grinding, thereby a shape having only aflat surface and a curved surface is obtained. Besides, a shape with nocorner may be obtained by forming a polygonal prism shape such as aquadratic prism and rounding off corners at which a top surface, abottom surface, and a side surface intersect and corner at which sidesurfaces intersect. Furthermore, a spherical shape, an ovoid shape, anoval spherical shape like a go stone, an oval spherical shape like arugby ball, a disc shape, or the like may be obtained.

The first conductive layer 711 formed over one surface of the dielectriclayer 710, the second conductive layer 712 formed over another surfaceof the dielectric layer 710 so as to oppose the first conductive layer711 through the dielectric layer, and the power feeding layer 713 areprovided. The first conductive layer 711 functions as an emitterelectrode. Moreover, the second conductive layer 712 functions as aground. The power feeding layer 713 is provided so as not to contact thefirst conductive layer 711 and the second conductive layer 712. Further,power is fed from the antenna to the layer including a semiconductorelement or from the layer including a semiconductor element to theantenna through the power feeding layer 713. It is to be noted thatpower may be fed by using a power feeding point instead of the powerfeeding layer.

Here, description is made on the structure of the antenna 703. Thedielectric layer 710 of the antenna can be formed of ceramic, an organicresin, a mixture of ceramic and an organic resin, or the like. Astypical examples of ceramic, alumina, glass, forsterite, and the likeare given. Furthermore, a plurality of kinds of ceramic may be mixed andused. In order to obtain a high dielectric constant, it is preferable toform the dielectric layer 710 by a ferroelectric material. As typicalexamples of the ferroelectric material, barium titanate (BaTiO₃), leadtitanate (PbTiO₃), strontium titanate (SrTiO₃), lead zirconate (PbZrO₃),lithium niobate (LiNbO₃), lead zirconate titanate (PZT), and the likeare given. Further, a plurality of kinds of ferroelectric materials maybe mixed and used.

Moreover, as an organic resin, a thermosetting curable resin or athermoplastic resin is appropriately used. As typical examples of anorganic resin, an epoxy resin, a phenol resin, a poly butadiene resin, aBT resin, vinyl benzyl, poly fumarate, a fluorocarbon resin, and thelike can be given. Further, a plurality of kinds of organic resinmaterials may be mixed and used.

In the case where the dielectric layer 710 is formed of a mixture ofceramic and an organic resin, it is preferable to disperse particulateceramic particles into the organic resin. At this time, it is preferablethat the ceramic be contained in the dielectric layer 710 by 20 to 60volume %. Further, a particle size is preferably 1 to 50 μm.

It is preferable that the dielectric constant of the dielectric layer710 be 2.6 to 150, or more preferably 2.6 to 40. By using aferroelectric material with a high dielectric constant, the volume ofthe antenna can be reduced.

The first conductive layer 711, the second conductive layer 712, and thepower feeding layer 713 can be formed of a metal selected from gold,silver, copper, palladium, platinum, and aluminum, an alloy thereof, orthe like. Moreover, the first conductive layer 711, the secondconductive layer 712, and the power feeding layer 713 can be formed by aprinting method or a plating method. Further, each conductive layer canbe formed by depositing a conductive layer over the dielectric film byan evaporation method or a sputtering method and etching a portionthereof.

Next, description is made with reference to FIG. 8 on the layer 701including a semiconductor element.

FIG. 8 is a sectional view of a portion of the layer 701 including asemiconductor element. Over a substrate 800, element isolating regions801 a to 801 e are formed, between each of which a semiconductor element802 such as a field effect transistor is formed.

The semiconductor element 802 includes a gate insulating film 803 formedover a single crystal semiconductor substrate, a gate electrode 804formed over the gate insulating film, a source region and a drain region805 a and 805 b in the single crystal semiconductor substrate, aninterlayer insulating layer 811 formed over the gate electrode, and asource wire and a drain wire 809 a and 809 b connected to the sourceregion and the drain region 805 a and 805 b respectively. It is to benoted that sidewalls 807 a and 807 b formed on side surfaces of the gateelectrode 804 and the gate insulating film 803 and low concentrationimpurity regions 806 a and 806 b covered with the sidewalls 807 a and807 b in the single crystal semiconductor substrate may be included aswell.

The substrate 800 is a single crystal semiconductor substrate or acompound semiconductor substrate, which is typically an n-type or p-typesingle crystal silicon substrate, a GaAs substrate, an InP substrate, aGaN substrate, a SiC substrate, a sapphire substrate, a ZnSe substrate,or the like. Moreover, an SOI substrate (Silicon On Insulator) can alsobe used. In this embodiment mode, an n-type single crystal siliconsubstrate is used as the substrate 800.

The element isolating regions 801 a to 801 e are formed by a knownselective oxidation method (LOCOS (Local Oxidation of Silicon) method),a trench isolation method, or the like. Here, a silicon oxide layer isformed by the trench isolation method as the element isolating regions801 a to 801 e.

The gate insulating film 803 is formed by thermally oxidizing the singlecrystal semiconductor substrate. The gate electrode 804 may be formed ofa polycrystal silicon layer with a thickness of 100 to 300 nm or astacked-layer structure formed by providing a silicide layer such as atungsten silicide layer, a molybdenum silicide layer, and a cobaltsilicide layer over the polycrystal silicon layer. Further, a tungstennitride layer and a tungsten layer may be stacked over the polycrystalsilicon layer.

The source region and the drain region 805 a and 805 b can be formed ofan n⁺ region formed by adding phosphorus to a p-well region and a p⁺region formed by adding boron to an n-well region. The low concentrationimpurity regions 806 a and 806 b can be formed of an n⁻ region formed byadding phosphorus to a p-well region and a p⁻ region formed by addingboron to an n-well region. It is to be noted that silicide such asmanganese silicide, tungsten silicide, titanium silicide, cobaltsilicide, and nickel silicide may be included in the source region andthe drain region 805 a and 805 b. By providing silicide to the surfacesof the source region and the drain region, connection resistance betweenthe source wire and the drain wire and the source region and the drainregion can be reduced.

The sidewalls 807 a and 807 b can be formed by forming an insulatinglayer of silicon oxide over the substrate by a CVD method and applyinganisotropic etching to the insulating layer by an ME (Reactive IonEtching) method.

An interlayer insulating layer 808 is formed of an inorganic insulatingmaterial such as silicon oxide and silicon oxynitride or an organicinsulating material such as an acryl resin and a polyimide resin. In thecase of employing a coating method such as spin coating or a rollcoater, silicon oxide formed by applying an insulating film materialdissolved in an organic solvent and then by thermal process to form aninsulating layer may be used. Here, the interlayer insulating layer 808is formed of silicon oxide.

The source wire and the drain wire 809 a and 809 b are preferably formedof a combination of a low resistance material such as aluminum (Al) anda barrier metal using a high melting point metal material such astitanium (Ti) and molybdenum (Mo), for example, a stacked-layerstructure of titanium (Ti) and aluminum (Al) and a stacked-layerstructure of molybdenum (Mo) and aluminum (Al).

The layer 701 including a semiconductor element includes a semiconductorelement such as a resistor and a capacitor in addition to a field effecttransistor.

The interlayer insulating layer 811 is formed over the interlayerinsulating layer 808 and the source wire and the drain wire 809 a and809 b. The interlayer insulating layer 811 is formed similarly to theinterlayer insulating layer 808. Moreover, over the interlayerinsulating layer 808, connecting terminals 812 and 813 connected to thesemiconductor element 802 are provided.

Moreover, an insulating layer 814 to cover portions of the connectingterminals 812 and 813 and the interlayer insulating layer 811 may beformed. The interlayer insulating layer 811 which functions as aprotective layer is preferably formed of silicon nitride, silicon oxide,silicon nitride oxide, silicon oxynitride, DLC (Diamond-Like Carbon), orthe like.

The conductive layers 702 a and 702 b which connect between the antenna703 and the layer 701 including a semiconductor element are formed of abump, a conductive paste, an anisotropic conductive adhesive, ananisotropic conductive film, or the like. Further, a bump and aconductive paste may be used in combination. Furthermore, a bump and ananisotropic conductive adhesive, or a bump and an anisotropic conductivefilm may be used in combination. In these cases, a conductive layer anda connecting terminal are connected through the bump and the conductiveparticles.

An anisotropic conductive film and an anisotropic conductive adhesiveare adhesive organic resins in which conductive particles having theparticle size of about several nm to several μm are dispersed. An epoxyresin, a phenol resin, or the like can be given as an organic resin.Moreover, conductive particles are formed of one or a plurality ofelements selected from gold, silver, copper, palladium, or platinum.Alternatively, a multi-layer structure of these elements may be employedas well. Further, conductive particles formed by coating resin particleswith a thin film formed of one or a plurality of metals selected fromgold, silver, copper, palladium, or platinum may be used as well.

An under-fill 704 has a function to reinforce the connecting portionbetween the layer 701 including a semiconductor element and the antenna703 and protect it from the entering of moisture, and can be formedusing an epoxy resin, an acrylic resin, a polyimide resin, or the like.

A wireless chip of the invention can also have a structure as shown inFIG. 7B.

An antenna included in a wireless chip shown in FIG. 7B is formed byforming a hole for inserting the layer 701 including a semiconductorelement after forming the dielectric layer 710. Then, the firstconductive layer 711 is formed over a surface of the dielectric layer710. The layer 701 including a semiconductor element is inserted andthen the second conductive layer 712 and the power feeding layer 713 areformed.

Here, the power feeding layer 713 of the antenna and the connectingterminal 704 a formed over a surface of the layer 701 including asemiconductor element are connected through the conductive layer 702 a.The connecting terminal 704 b formed over a surface of the layer 701including a semiconductor element and the conductive layer 712 whichfunctions as a ground of the antenna are connected through theconductive layer 702 b. Moreover, a connecting portion between theantenna 703 and the layer 701 including a semiconductor element may befilled with the under-fill 704.

A wireless chip of the invention is not limited to be formed by theaforementioned method. However, as described above, by forming the layer701 including a semiconductor element inside the dielectric layer 710included in the antenna, a shape with only a flat surface and a curvedsurface without a projection and a depression can be obtained, therebythe safety can be improved.

According to the invention, a wireless chip which is small in size,favorable in communication property, and inexpensive can be provided.Further, a wireless chip of the invention has a cylindrical shape inwhich outer edge portions thereof have curved surfaces. In specific,corners at which a top surface, a bottom surface, and a side surface ofthe cylindrical shape intersect are rounded off by grinding, thereby ashape having only a flat surface and a curved surface is obtained.Besides, a shape with no corner may be obtained by forming a polygonalprism shape such as a quadratic prism and rounding off corners at whicha top surface, a bottom surface, and side surfaces intersect and cornersat which side surfaces intersect. Furthermore, a spherical shape, anovoid shape, an oval spherical shape like a go stone, an oval sphericalshape like a rugby ball, a disc shape, or the like may be obtained,thereby a wireless chip can be provided with high safety which does notcause an injury or the like when touched.

It is to be noted that this embodiment mode can be implemented incombination with the aforementioned embodiment mode.

Embodiment Mode 3

This embodiment mode describes steps of forming the semiconductorelement in the layer including a semiconductor element described inEmbodiment Modes 1 and 2 by using different materials. In thisembodiment mode, a layer including a semiconductor element is formed byforming a semiconductor element having an organic semiconductor layerover an insulating substrate as an example.

For example, a flexible substrate has lower thermal resistance ascompared to a non-flexible substrate such as a glass substrate.Therefore, in the case of forming a semiconductor element over aflexible substrate, it is preferable to use an organic semiconductor.The layer including a semiconductor element formed of an organicsemiconductor is formed by forming a semiconductor element over aflexible substrate and an insulating layer to cover the semiconductorelement. A connecting terminal to be connected to a wire of thesemiconductor element is formed over the surface of the layer includingthe semiconductor element.

Here, description is made with reference to FIGS. 9A and 9B onstructures of the semiconductor element formed of an organicsemiconductor. FIG. 9A shows an example of using a staggered transistor.A semiconductor element 900 is provided over a flexible substrate 901.The semiconductor element 900 is formed of a gate electrode 902, aninsulting layer 903 which functions as a gate insulating film, asemiconductor layer 904 which is overlapped with the gate electrode andthe insulating layer which functions as a gate insulating film, andwires 905 and 906 connected to the semiconductor layer 904. It is to benoted that the semiconductor layer is in contact with the insulatinglayer 903 which functions as a gate insulating film and the wires 905and 906.

The gate electrode 902 can be formed, for example, by a method to form apredetermined pattern by discharging liquid droplets of a compositioncontaining fine particles from minute orifices (hereinafter referred toas a droplet discharge method in this specification) and to apply dryingand baking treatment. Furthermore, the gate electrode 902 can be formedby printing a paste containing particles over a flexible substrate by aprinting method and applying drying and baking treatment. As a typicalexample of the particles, particles containing any one of gold, copper,an alloy of gold and silver, an alloy of gold and copper, an alloy ofsilver and copper, and an alloy of gold, silver, and copper as a maincomponent may be used. Further, particles containing conductive oxidesuch as indium tin oxide (ITO) as a main component may also be used.

The insulating layer 903 which functions as a gate insulating film canbe formed by using a similar material and method to those of the gateinsulating layer 405 described with reference to FIGS. 3A to 3D.However, in the case of forming the insulating layer by applying aninsulating film material, which is dissolved in an organic solvent, by aspin coating method, a roll coating method, or the like and applyingthermal treatment, it is preferable to perform the thermal treatment ata temperature lower than the heat resistance temperature of the flexiblesubstrate.

The semiconductor layer 904 is formed of a polycyclic aromatic compound,a conjugated double bond compound, phthalocyanine, a charge-transfercomplex, or the like. For example, anthracene, tetracene, pentacene, 6T(hexathiophene), TCNQ (tetracyanoquinodimethane), PTCDA(perylenetetracarboxylic dianhydride), NTCDA (naphthalenetetracarboxylicdianhydride), or the like can be used. As a specific example of anorganic high molecular compound material, a π-conjugated high molecularcompound, a carbon nanotube, polyvinyl pyridine, a phthalocyanine metalcomplex, or the like can be given. In particular, polyacetylene,polyaniline, polypyrrole, polythienylene, a polythiophene derivative,poly(3 alkylthiophene), a polyparaphenylene derivative, or a polyparaphenylene vinylene derivative can be employed, which is π-conjugatedhigh molecular compound whose skeleton is formed of conjugated doublebonds.

Further, the organic semiconductor film may be formed by a method toform a film having a uniform film thickness. The film thickness is setto 1 to 1000 nm, and preferably 10 to 100 nm. As a specific method, anevaporation method, a spin coating method, a barcode method, a solutioncasting method, a dip coating method, a screen printing method, a rollcoating method, or a droplet discharge method can be used.

The wires 905 and 906 can be formed using a similar material and methodto those of the gate electrode 902.

FIG. 9B shows an example of using a coplanar transistor. Thesemiconductor element 900 is provided over the flexible substrate 901.In the semiconductor element 900, the gate electrode 902, the insulatinglayer 903 which functions as a gate insulating film, the wires 905 and906, and the semiconductor layer 904 overlapped with the gate electrodeand the insulating layer 903 which functions as a gate insulating filmare formed. Further, the wires 905 and 906 are in contact with theinsulating layer which functions as the gate insulating layer and thesemiconductor layer.

By forming a semiconductor element using an organic semiconductor layerover a flexible substrate as described above, a very thin layerincluding a semiconductor element can be formed. By forming the antennadescribed in Embodiment Modes 1 and 2 and attaching the antenna and thelayer including a semiconductor element as shown in FIG. 2D so as to beelectrically connected (for example, by using an anisotropic conductivefilm, or the like), a wireless chip having a shape without projectionand depression can be formed.

The invention can provide a wireless chip which is small in size,favorable in a communication property, and inexpensive. Further, awireless chip of the invention has a cylindrical shape in which outeredge portions thereof have curved surfaces. In specific, corners atwhich a top surface, a bottom surface, and a side surface of thecylindrical shape intersect are rounded off by grinding, thereby a shapehaving only a flat surface and a curved surface is obtained. Besides, ashape with no corner may be obtained by forming a polygonal prism shapesuch as a quadratic prism and rounding off corners at which a topsurface, a bottom surface, and side surfaces intersect and corners atwhich side surfaces intersect. Furthermore, a spherical shape, an ovoidshape, an oval spherical shape like a go stone, an oval spherical shapelike a rugby ball, a disc shape, or the like may be obtained, thereby awireless chip can be provided with high safety which does not cause aninjury or the like when touched.

It is to be noted that this embodiment mode can be freely implemented incombination with the aforementioned embodiment modes.

Embodiment Mode 4

In this embodiment mode, description is made with reference to FIGS. 10Ato 10C on a wireless chip coated with a resin or the like, which is adifferent mode than the aforementioned Embodiment Modes 1 to 3.

For example, in the case where a wireless chip having only a flatsurface and/or a curved surface cannot be formed when the workabilityand the manufacturing cost of a dielectric layer are considered, awireless chip formed into an unspecified shape can be coated with aprotective layer such as a resin. FIG. 10A shows a wireless chip 1001coated with a protective layer 1002 such as a resin.

By coating the wireless chip 1001 with the protective layer 1002 such asa resin, the wireless chip with an ovoid shape, a spherical shape, anoval spherical shape like a go stone, an oval spherical shape like arugby ball, a disc shape, or the like can be formed. Alternatively, awireless chip having a cylindrical shape (or a polygonal prism shape) inwhich outer edge portions thereof has curved surfaces can be formed byusing a casting mold or rounding off corners by grinding.

In a wireless chip of the invention which wirelessly communicates with areader/writer through electromagnetic waves, a wireless tag can becoated with a protective layer formed of a substance which does notinterrupt the communication.

FIGS. 10B and 10C show sectional views of wireless chips each coatedwith a protective layer such as a resin. As shown in FIG. 10B, thewireless chip 1001 can be directly coated with a protective layer 1003such as a resin. Furthermore, as shown in FIG. 10C, a protective layer1004 is formed into a capsule and the wireless chip 1001 is incorporatedtherein, and a filler material 1005 may be provided between theprotective layer 1004 and the wireless chip 1001.

As an example of a protective layer to coat a wireless chip, an organicresin, an inorganic resin, diamond-like carbon (DLC), and the like canbe given. Further, when the protective layer contains silicon nitride,silicon oxide, silicon nitride oxide, silicon oxynitride, carbonnitride, or the like, the layer including a semiconductor element can beprotected from an alkali metal which degrades the function of thesemiconductor.

The method to form the outer shape by coating the wireless tag asdescribed above can be applied to the case where the shape of thewireless tag cannot be determined only by the dielectric layer since thelayer including a semiconductor element formed of a silicon wafer isthick and the case where it costs rather less to coat the wireless tagthan shaping the dielectric layer.

Moreover, by coating the outermost surface of a wireless chip with aresin, DLC (Diamond-Like Carbon), or the like to shape the chip into ashape with a curved surface as described in the invention, a wirelesschip with high safety which does not harm a human body even when thewireless chip is drunk by mistake

Further, by coating the outermost surface of a wireless chip, physicalstrength can be enhanced and a recyclable wireless chip which can beused repeatedly can be provided.

It is to be noted that this embodiment mode can be freely implemented incombination with the aforementioned embodiment modes.

Embodiment Mode 5

In this embodiment mode, description is made with reference to FIGS. 11Ato 11C on applications of a wireless chip.

A wireless chip which is small in size and can be inexpensivelymanufactured can be attached to an object to manage the retail thereof.In this manner, when a large number of wireless chips are used for theretailing of objects, the wireless chip ultimately reaches a consumer.The ultimate consumers are general public including people who have noknowledge about the wireless chip and the automatic recognitiontechnique. Therefore, for example, there is a risk of an unexpectedaccident such as injuring a skin or drinking by mistake. Moreover, thereis a problem in the disposal method and recycling of the wireless chipafter use.

In view of these problems, the invention provides a method to wrap orincorporate a wireless chip in a box, a bag, wrapping paper, a freegift, or the like with a safe size and shape that the consumers caneasily recognize, and attach it to an object, thereby managing theobjects using the wireless chip.

For example, as shown in FIG. 11A, a wireless chip can be put in a bag1101 and attached to an object 1102 such as a plastic bottle. By puttinga wireless chip in a bag having a hook as shown in the drawing, aretailer can attach the wireless chip easily to a product. Furthermore,the bag has a size which can be recognized at a glance, therefore, aproduct without a wireless chip can be recognized at a glance as well.Moreover, a consumer can also recognize the presence of the wirelesschip.

Further, as shown in FIG. 11B, a wireless chip can be wrapped inwrapping paper 1103 and attached to an object 1104 such as a vegetable.By wrapping a wireless chip as shown in the drawing, the wireless chipcan be easily attached when bundling the products such as vegetables.Moreover, when a consumer cooks the vegetables, the wireless chip can besecurely taken off before cooking.

Furthermore, as shown in FIG. 11C, a wireless chip can be incorporatedin a free gift 1105 or the like and then attached to an object 1106, forexample, in the case of selling an expensive bag or the like. Byincorporating a wireless chip in a pretty mascot as shown in thedrawing, the image of the product may be improved. Further, a wirelesschip incorporated in the mascot is treated well, therefore, the wirelesschip may be able to be recycled.

By using a wireless chip as described above, a retailer who uses thewireless chip and a consumer who buys the product can recognize thewireless chip as it is. Moreover, by using a safe material for theoutermost surface of an object to wrap or incorporate the wireless chip,an unexpected accident can be avoided. Further, wastes with wirelesschips can be sorted to be collected.

Further, the wrapping paper, bag, and the like which incorporate thewireless tags can be easily collected in the retail shop, therefore, thewireless chips can be recycled. Wrapping or incorporating the wirelesschip can prevent the wireless chip from deteriorating. Furthermore, bychanging the object which wraps or incorporates the wireless chip, thewireless chip can be recycled.

It is to be noted that this embodiment mode can be freely implemented incombination with the aforementioned embodiment modes.

Embodiment Mode 6

In this embodiment mode, description is made with reference to FIGS. 12Ato 12D on the kinds of an antenna which forms a wireless chip of theinvention.

First, dielectric layers 1201, 1211, 1221, and 1241 as shown in FIGS.12A to 12D are formed. The aforementioned dielectric layer has acylindrical shape with outer edge portions having curved surfaces. Inspecific, the aforementioned dielectric layer has a cylindrical shapeand a curved surface in an outer edge portion. In specific, corners atwhich a top surface, a bottom surface, and a side surface of thecylindrical shape intersect are rounded off by grinding, thereby a shapehaving only a flat surface and a curved surface is obtained. Besides, ashape with no corner may be obtained by forming a polygonal prism shapesuch as a quadratic prism and rounding off corners at which a topsurface, a bottom surface, and side surfaces intersect and corners atwhich side surfaces intersect. Furthermore, a spherical shape, an ovoidshape (FIG. 23D), an oval spherical shape like a go stone, an ovalspherical shape like a rugby ball, a disc shape, or the like may beobtained. In each of FIGS. 12A to 12D, a dielectric layer formed in acylindrical shape and then its corners are removed by rounding is shownas an example. However, the invention is not limited to this.

First, an antenna shown in FIG. 12A includes a first conductive layer1202 which functions as an emitter electrode, a dielectric layer 1201, asecond conductive layer 1203 which functions as a ground, a powerfeeding point 1204, and a power feeder which is formed in a through holeprovided in the first conductive layer, the dielectric layer, and thesecond conductive layer and connected to the power feeding point. It isto be noted that the power feeder is connected to the first conductivelayer at the power feeding point but not connected to the secondconductive layer. By forming the first conductive layer 1202 whichfunctions as an emitter electrode into a circular shape and rounding offtwo regions 1205 which are symmetric with respect to a point, theantenna can receive circularly polarized electromagnetic waves. Further,in the case where the first conductive layer 1202 is in a rectangularshape, the antenna can receive vertically polarized electromagneticwaves.

Next, an antenna shown in FIG. 12B includes a first conductive layer1212 which functions as an emitter electrode, a dielectric layer 1211, asecond conductive layer 1213 which functions as a ground, a powerfeeding point 1214, and a power feeder which is formed in a through holeprovided in the first conductive layer, the dielectric layer, and thesecond conductive layer, and connected to the power feeding point. It isto be noted that the power feeder is connected to the first conductivelayer at the power feeding point but not connected to the secondconductive layer. By forming the first conductive layer 1212 whichfunctions as an emitter electrode into a rectangular shape and roundingoff two corners 1215 which are symmetric with respect to a point, theantenna can receive circularly polarized electromagnetic waves. Further,in the case where the first conductive layer 1212 is in a rectangularshape, the antenna becomes an antenna for vertically polarized waves.

Further, an antenna shown in FIG. 12C includes a first conductive layer1222 which functions as an emitter electrode, a dielectric layer 1221, asecond conductive layer 1223 which functions as a ground, and a powerfeeding layer 1224. By forming the first conductive layer 1222 whichfunctions as an emitter electrode into a rectangular shape and roundingoff two corners 1225 which are symmetric with respect to a point, theantenna can receive circularly polarized electromagnetic waves. Thepower feeding layer 1224 and the first conductive layer 1222 whichfunctions as an emitter electrode are capacitively coupled through agap. Moreover, the power feeding layer 1224 can be formed over the sidesurface of the dielectric layer and thus mounted on the surface.

Each of the antennas shown in FIGS. 12A to 12C has the second conductivelayer which functions as a ground over one surface of the dielectriclayer, therefore, the first conductive layer side has directivity, towhich electromagnetic waves are emitted.

Moreover, an antenna shown in FIG. 12D includes a first conductive layer1242 which functions as an emitter electrode, a dielectric layer 1241, asecond conductive layer 1243 which functions as a ground, and a powerfeeding layer 1244. Further, orthogonal slits 1245 are diagonally formedin the first conductive layer 1242. That is, a cross slit is provided.Therefore, the dielectric layer 1241 is exposed in a cross shape. Thefirst conductive layer 1242 which functions as an emitter electrode andthe power feeding layer 1244 are capacitively coupled through a gap.

In particular, by using an antenna for circularly polarized waves,satellite communication such as GPS (Global Positioning System) (1.5GHz) and satellite digital broadcasting (2.6 GHz), PAN (Personal AreaNetwork) communication such as wireless LAN (Local Area Network) (2.4GHz, 5.2 GHz), wireless communication for portable information devices(2.4 GHz), UWB (Ultra Wide Band) (3 to 10 GHz), data communication ofthird generation, and packet communication can be carried out.

Moreover, a wireless chip of the invention can be formed by using aknown antenna as well as the antennas shown in FIGS. 12A to 12D.

It is to be noted that this embodiment mode can be freely implemented incombination with the aforementioned embodiment modes.

Embodiment Mode 7

In this embodiment mode, description is made with reference to FIGS. 13Ato 13C on circuit configuration examples of wireless chips of theinvention.

A wireless chip 20 of the invention wirelessly communicates with areader/writer. The wireless chip 20 includes a power source circuit 11,a clock generating circuit 12, a data demodulation/modulation circuit13, a control circuit 14 which controls another circuit, an interfacecircuit 15, a memory circuit 16, a bus 17, and an antenna 18 as shown inFIG. 13A.

Moreover, as shown in FIG. 13B, the wireless chip 20 of the inventionmay include a central processing unit 21 in addition to the power sourcecircuit 11, the clock generating circuit 12, the datademodulation/modulation circuit 13, the control circuit 14 whichcontrols another circuit, the interface circuit 15, the memory circuit16, the bus 17, and the antenna 18.

Further, as shown in FIG. 13C, the wireless chip 20 of the invention mayinclude a detection portion 30 formed of a detecting element 31 and adetecting circuit 32 in addition to the power source circuit 11, theclock generating circuit 12, the data demodulation/modulation circuit13, the control circuit 14 which controls another circuit, the interfacecircuit 15, the memory circuit 16, the bus 17, the antenna 18, and thecentral processing unit 21. Here, the central processing unit 21includes a CPU, an arithmetic processing circuit, or the like. Thedetecting element 31 includes a sensor for measuring the amount,concentration, and the like of a substance.

A small and multifunctional wireless chip can be formed by forming thedetection portion 30 formed of the detecting element 31 and thedetecting circuit 32, or the like in addition to the power sourcecircuit 11, the clock generating circuit 12, the datademodulation/modulation circuit 13, the control circuit 14 whichcontrols another circuit, the interface circuit 15, the memory circuit16, the bus 17, the central processing unit 21 in the layer including asemiconductor element described in Embodiment Modes 1 to 3.

The power source circuit 11 generates various power sources to besupplied to each circuit in the wireless chip 20 based on alternatingsignals inputted from the antenna 18. The clock generating circuit 12generates various clock signals to be supplied to each circuit in thewireless chip 20 based on alternating signals inputted from the antenna18. The data demodulation/modulation circuit 13 has a function todemodulate/modulate data to communicate with the reader/writer 19. Thecontrol circuit 14 which controls another circuit has a function tocontrol the memory circuit 16. The antenna 18 has a function totransmit/receive electromagnetic waves. The reader/writer 19 controls aprocess related to the communication, control, and data of the wirelesschip. It is to be noted that the wireless chip is not limited to havethe aforementioned structure and may have a structure where anotherelement such as a limiter circuit for a power source voltage anddedicated cryptographic hardware is additionally provided.

The memory circuit 16 includes one or a plurality selected from a DRAM,an SRAM, a FeRAM, a mask ROM, a PROM, an EPROM, an EEPROM, a flashmemory, and an organic memory.

It is to be noted that an organic memory includes a pair of electrodeswhich sandwich a layer containing an organic compound. Further, anorganic memory includes a mixed layer of an organic compound and aninorganic compound between a pair of electrodes. As a typical example ofan organic compound, a substance of which crystallinity, conductivity,or shape changes by an electrical effect or light irradiation is used.As a typical substance, conjugated polymer to which a compound whichgenerates acid by absorbing light (photoacid generator) is doped, anorganic compound having a high hole transporting property, or an organiccompound having a high electron transporting property can be used.

Moreover, in the case of providing a mixed layer of an organic compoundand an inorganic compound between a pair of electrodes, an organiccompound having a high hole transporting property and an inorganiccompound which easily accepts electrons are preferably mixed. Further,it is preferable to mix an organic compound having a high electrontransporting property and an inorganic compound which easily giveselectrons. With such a structure, a lot of hole carriers and electroncarriers are generated in an organic compound which does not originallyhave almost any internal carriers, thereby excellent hole injecting andtransporting properties and electron injecting and transportingproperties can be obtained.

Au organic memory can realize the reduction in size and film thickness,and large capacity at the same time, therefore, a wireless chip can beformed small and light in weight by providing an organic memory as thememory circuit 16.

It is to be noted that this embodiment mode can be freely implemented incombination with the aforementioned embodiment modes.

Embodiment Mode 8

FIG. 14 shows an embodiment mode of a wireless chip of the invention.FIG. 14 is a sectional view of a wireless chip. In this embodiment mode,description is made on a structure of a wireless chip where a layerincluding a semiconductor element, a passive element, and an antenna arefixed by an anisotropic conductive adhesive, a conductive layer, or thelike.

As described in Embodiment Modes 1 to 3, a layer 1401 including asemiconductor element is formed. The layer 1401 including asemiconductor element and a passive element 1420 are fixed by ananisotropic conductive adhesive 1410. Here, the passive element 1420 isshown to be formed of a first passive element 1430 and a second passiveelement 1440. Moreover, a wire 1402 exposed to a surface of the layer1401 including a semiconductor element and a first wire 1421 of thepassive element 1420 are electrically connected through conductiveparticles in the anisotropic conductive adhesive 1410.

Further, the passive element 1420 and the antenna 1460 are fixed byconductive layers 1450 and 1451. A power feeding layer 1463 of theantenna 1460 and a second wire 1422 of the passive element 1420, and asecond conductive layer 1462 which functions as a ground of the antennaand a third wire 1423 are electrically connected through conductivelayers 1450 and 1451 respectively. The conductive layers 1450 and 1451are formed by curing conductive paste. As a typical example of aconductive layer formed by curing conductive paste, an alloy containinga plurality of tin (Sn), silver (Ag), bismuth (Bi), copper (Cu), indium(In), nickel (Ni), antimony (Sb), and zinc (Zn) is used. Moreover, ananisotropic conductive adhesive can also be used instead of theconductive layers 1450 and 1451.

Further, the first passive element 1430 includes insulating layers 1431to 1434 and conductive layers 1441 to 1443 provided between them, whichform one or more of a capacitor, an inductor, and a resistor. The secondpassive element 1440 similarly includes insulating layers 1434 to 1437and conductive layers 1444 to 1446 provided between them, which form oneor more of a capacitor, an inductor, and a resistor.

It is preferable that the dielectric constants of the insulating layers1431 to 1437 of the first passive element 1430 or the second passiveelement 1440 be 2.6 to 40. The conductive layers 1441 to 1446 are formedof a metal having high conductivity such as gold, silver, copper, andaluminum or an alloy formed of a plurality of them.

The first passive element 1430 and the second passive element 1440 areformed as follows. A conductive layer is formed by printing a metalhaving high conductivity such as gold, silver, copper, and aluminum oran alloy formed of a plurality of them by a printing method over a sheet(what is called a green sheet) with a thickness of 10 to 150 μm formedof ceramic containing aluminum oxide and silicon oxide. It is to benoted that a through hole may be formed in the green sheet andconductive paste may be filled in the through hole to form a plug ifrequired. Moreover, the green sheet may be formed by appropriatelymixing ceramic, an organic resin, and the like which form the dielectriclayer 1461 of the antenna 1460 described in Embodiment Mode 1 or 2. Thefirst passive element 1430 and the second passive element 1440 can beformed by thermocompression bonding of a plurality of green sheets overwhich such conductive layers are printed, processing them into apredetermined size, and baking them by heat at 800 to 1300° C. to formthe insulating layer and the conductive layer.

When a plurality of passive elements such as a capacitor, an inductor, aresistor, and a wire are used in combination, a front end moduleincluding a diplexer, and a low pass filter which constitute a highfrequency circuit, an isolator power amplifier module including anisolator, a coupler, an attenuator, and a power amplifier, a VCO(voltage control oscillator), a band pass filter (BPF), a stacked-layerfilter, a balun transformer, a dielectric filter, a coupler, aresonator, and the like can be formed. Here, a high frequency circuit isa circuit which operates with a frequency of several hundreds MHz toseveral tens GHz.

Further, a passive element and a layer including a semiconductor elementform a power source circuit, a clock generating circuit, and a datademodulation/modulation circuit as high frequency circuits, a controlcircuit which controls another circuit, an interface circuit, a memorycircuit, a central processing unit, a detecting element and a detectingcontrol circuit, and the like.

Moreover, similarly to Embodiment Mode 1, the layer 1401 including asemiconductor element may be fixed to a flexible substrate through anorganic resin layer.

A wireless chip of this embodiment mode is formed of an integratedcircuit formed by using a semiconductor element and a passive elementformed by stacking an insulating layer and a conductive film. Therefore,each circuit is highly integrated by elements with appropriatefunctions. By mounting a wireless chip of the invention to a wiringsubstrate, the number of components can be reduced, which can reduce thearea of the wiring substrate and downsize an electronic device havingthe wiring substrate.

It is to be noted that this embodiment mode can be freely implemented incombination with the aforementioned embodiment modes.

Embodiment

In this embodiment, description is made on a method for forming asemiconductor element as an example.

FIGS. 15A to 15C show examples of a layer including a semiconductorelement which forms a wireless chip of the invention. It is to be notedin FIGS. 15A to 15C that FIG. 15B corresponds to a cross sectional viewalong a-b in FIG. 15A and FIG. 15C corresponds to a sectional view alongc-d in FIG. 15A.

The layer including a semiconductor element shown in FIGS. 15A to 15Cincludes semiconductor films 1503 a and 1503 b provided over a substrate1501 with an insulating film 1502 interposed therebetween, a gateelectrode 1505 provided over the semiconductor films 1503 a and 1503 bwith a gate insulating film 1504 interposed therebetween, insulatingfilms 1506 and 1507 provided so as to cover the gate electrode, and aconductive film 1508 which is electrically connected to a source regionor a drain region of the semiconductor films 1503 a and 1503 b andprovided over the insulating film 1507. It is to be noted in FIGS. 15Ato 15C that an n-type thin film transistor 1510 a of which channelregion is a portion of the semiconductor film 1503 a and a p-channelthin film transistor 1510 b of which channel region is a portion of thesemiconductor film 1503 b are provided, however, the invention is notlimited to this configuration. For example, in FIGS. 15A to 15C, an LDDregion is provided in the n-type thin film transistor 1510 a but not inthe p-type thin film transistor 1510 b, however, it can be provided inboth of the transistors or no transistors.

The substrate 1501 may be formed of a glass substrate such as bariumborosilicate glass and alumino borosilicate glass, a quartz substrate, aceramic substrate, a metal substrate including stainless steel, or thelike. Besides, a substrate containing a flexible synthetic resin such asplastic or acrylic represented by polyethylene terephthalate (PET),polyethylene naphthalate (PEN), or polyether sulfone (PES) can also beused. By using a flexible substrate, a layer having a semiconductorelement which can be bent can be formed. In addition, as such asubstrate has no limit in its area and size, for example, a rectangularsubstrate having a side of 1 meter or longer can be used as thesubstrate 1501, thereby the productivity can be drastically improved.Such an advantage is a big dominance as compared to the case to use acircular silicon substrate.

The insulating film 1502 functions as a base film and prevents an alkalimetal such as Na and alkaline earth metal from dispersing into thesemiconductor films 1503 a and 1503 b and affecting the characteristicsof the semiconductor element. As the insulating film 1502, a singlelayer structure of an insulating film containing oxygen or nitrogen,such as silicon oxide (SiO_(x)), silicon nitride (SiN_(x)), siliconoxynitride (SiO_(x)N_(y)) (x>y), silicon nitride oxide (SiN_(x)O_(y))(x>y), or the like or a stacked-layer structure of these. For example,in the case of providing the insulating film 1502 as a two-layerstructure, it is preferable that a silicon nitride oxide film beprovided as a first layer insulating film and a silicon oxynitride filmbe provided as a second layer insulating film. Further, in the case ofproviding the insulating film 1502 as a three-layer structure, it ispreferable that a silicon oxynitride film be provided as a first layerinsulating film, a silicon nitride oxide film be provided as a secondlayer insulating film, and a silicon oxynitride film be provided as athird layer insulating film.

The semiconductor films 1503 a and 1503 b can be formed of an amorphoussemiconductor or a semi-amorphous semiconductor (SAS). In addition, apolycrystal semiconductor film may also be used. An SAS has anintermediate structure between amorphous and crystalline structures(including single crystal and poly crystal structures) and a tertiarystate which is stable in terms of free energy, and including acrystalline region having a short distance order and lattice distortion(also referred to as a microcrystal semiconductor film) can be used asthe active layer of the TFT. In the semi-amorphous semiconductor film, acrystal region having a grain diameter of 0.5 to 20 nm is included in atleast one region of the film. In the case where an SAS contains siliconas a major component, the Raman spectrum shifts to the lower side of awave number of 520 cm⁻¹. In addition, in the semi-amorphoussemiconductor film, diffraction peaks of (111) and (220) derived from aSi crystal lattice are observed in x-ray diffraction. The semi-amorphoussemiconductor film includes hydrogen or halogen at least 1 atom % forterminating a dangling bond. An SAS is formed by performing glowdischarging decomposition (plasma CVD) of a silicide gas. As thesilicide gas, SiH₄ as well as Si₂H₆, SiH₂Cl₂, SiHCl₃, SiCl₄, SiF₄, orthe like can be used. Moreover, GeF₄ may be mixed as well. The silicidegas may be diluted with H₂, or H₂ and one or more of rare gas elementsselected from He, Ar, Kr, and Ne. A dilution ratio is within the rangeof 2 to 1000 times. Pressure is roughly within the range of 0.1 to 133Pa; power frequency is 1 to 120 MHz, preferably 13 to 60 MHz; and asubstrate heating temperature is 300° C. or lower. The impurities ofatmospheric components such as oxygen, nitrogen or carbon as an impurityelement within a film is preferably at most 1×10²⁰ cm⁻¹, in particular,oxygen concentration is at most 5×10¹⁹/cm³, preferably, at most1×10¹⁹/cm³. Here, a known method (a sputtering method, an LPCVD method,a plasma CVD method, or the like) is used to form an amorphoussemiconductor film with a material containing silicon (Si) as a maincomponent (for example, Si_(x)Ge_(1-x) or the like), and then theamorphous semiconductor film is crystallized by a known crystallizationmethod such as a laser crystallization method, a thermal crystallizationmethod using RTA or an annealing furnace, and a thermal crystallizationmethod using a metal element.

The gate insulating film 1504 can be formed of a single layer structureof an insulating film containing oxygen or nitrogen, such as siliconoxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiO_(x)N_(y)) (x>y), and silicon nitride oxide (SiN_(x)O_(y)) (x>y), ora stacked-layer structure of these.

The insulating film 1506 can be formed of a single layer structure of aninsulating film containing oxygen or nitrogen, such as silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y))(x>y), and silicon nitride oxide (SiN_(x)O_(y)) (x>y) or a filmcontaining carbon such as DLC (Diamond-Like Carbon), or a stacked-layerstructure of these.

The insulating film 1507 can be formed of a single layer structure or astacked-layer structure of an organic material such as epoxy, polyimide,polyamide, polyvinyl phenol, benzocyclobutene, and acrylic, or asiloxane resin, as well as an insulating film containing oxygen ornitrogen, such as silicon oxide (SiO_(x)), silicon nitride (SiN_(x)),silicon oxynitride (SiO_(x)N_(y)) (x>y), and silicon nitride oxide(SiN_(x)O_(y)) (x>y) or a film containing carbon such as DLC(Diamond-Like Carbon). It is to be noted that a siloxane materialcorresponds to a resin containing a Si—O—Si bond. Siloxane has askeleton of a bond of silicon (Si) and oxygen (O). As a substituent, anorganic group containing at least hydrogen (for example, an alkyl groupand an aromatic carbon hydride) or a fluoro group may be used.Alternatively, an organic group containing at least hydrogen and afluoro group may be used as a substituent. It is to be noted that theinsulating film 1507 may be directly provided to cover the gateelectrode 1505 without providing the insulating film 1506 in the layerincluding a semiconductor element shown in FIGS. 15A to 15C.

The conductive film 1508 can be formed of a single layer structure or astacked-layer structure of one element selected from Al, Ni, C, W, Mo,Ti, Pt, Cu, Ta, Au, and Mn or an alloy containing a plurality of theseelements. For example, an Al alloy containing C and Ti, an Al alloycontaining Ni, an AI alloy containing C and Ni, an Al alloy containing Cand Mn, and the like can be used as a conductive film formed of an alloycontaining a plurality of the aforementioned elements. Further, in thecase of forming the conductive film 1508 as a stacked-layer structure,Al and Ti can be stacked.

In FIGS. 15A to 15C, the n-type thin film transistor 1510 a hassidewalls in contact with the side surfaces of the gate electrode 1505,a source region and a drain region formed by selectively addingimpurities which impart n-type conductivity to the semiconductor film1503 a, and LDD regions provided beneath the sidewalls. Moreover, thep-type thin film transistor 1510 b has sidewalls in contact with sidesurfaces of the gate electrode 1505, and a source region and a drainregion formed by selectively adding impurities which impart p-typeconductivity to the semiconductor film 1503 b.

It is to be noted that in the layer including a semiconductor elementwhich constitutes the wireless chip of the invention, at least one ofthe substrate 1501, the insulating film 1502, the semiconductor films1503 a and 1503 b, the gate insulating film 1504, the insulating film1506, or the insulating film 1507 is oxidized or nitrided by plasmatreatment, thereby the semiconductor film or the insulating film isoxidized or nitrided. In this manner, by oxidizing or nitriding thesemiconductor film or the insulating film by plasma treatment, theproperty of the surface of the semiconductor film or the insulating filmis changed. As a result, a more dense insulating film can be formed ascompared to an insulating film formed by a CVD method or a sputteringmethod. Therefore, a defect such as a pinhole can be suppressed and thecharacteristics or the like of the layer including a semiconductorelement can be improved.

Hereinafter described with reference to the drawings is a method forforming a layer including a semiconductor element by plasma treatment.In specific, description is made on the case of forming a layerincluding a semiconductor element by oxidizing or nitriding thesubstrate 1501, the insulating film 1502, the semiconductor films 1503 aand 1503 b, the gate insulating film 1504, the insulating film 1506, orthe insulating film 1507.

Here, description is made with reference to the drawings on a method forforming a layer including a semiconductor element by applying plasmatreatment to the semiconductor films 1503 a and 1503 b or the gateinsulating film 1504 in FIGS. 15A to 15C to oxidize or nitride thesemiconductor films 1503 a and 1503 b or the gate insulating film 1504.

First, the edge portions of an island-shaped semiconductor film providedover a substrate are formed almost vertically.

The island-shaped semiconductor films 1503 a and 1503 b are formed overthe substrate 1501 (FIGS. 16A-1 and 16A-2). The island-shapedsemiconductor films 1503 a and 1503 b are formed by forming an amorphoussemiconductor film using a material containing silicon (Si) as a maincomponent (for example, Si_(x)Ge_(1-x) or the like) or the like by aknown method (a sputtering method, an LPCVD method, a plasma CVD method,or the like) over the insulating film 1502 which is formed in advanceover the substrate 1501, and then the amorphous semiconductor film iscrystallized and selectively etched. It is to be noted that theamorphous semiconductor film can be crystallized by a knowncrystallization method such as a laser crystallization method, a thermalcrystallization method using RTA or an annealing furnace, a thermalcrystallization method using a metal element which promotescrystallization, or a method using these methods in combination. It isto be noted in FIGS. 16A to 16D that the edge portions of theisland-shaped semiconductor films 1503 a and 1503 b are formed almostvertically (θ=85 to 100°).

Next, the semiconductor films 1503 a and 1503 b are oxidized or nitridedby plasma treatment to form oxide films or nitride films 1521 a and 1521b (hereinafter also referred to as insulating films 1521 a and 1521 b)over the surfaces of the semiconductor films 1503 a and 1503 brespectively (FIGS. 16B-1 and 16B-2). In the case of using Si for thesemiconductor films 1503 a and 1503 b, for example, silicon oxide(SiO_(x)) or silicon nitride (SiN_(x)) is formed as the insulating films1521 a and 1521 b. Moreover, after the semiconductor films 1503 a and1503 b are oxidized by plasma treatment, they may be nitrided by plasmatreatment again. In this case, silicon oxide (SiO_(x)) is formed incontact with the semiconductor films 1503 a and 1503 b and siliconnitride oxide (SiN_(x)O_(y)) (x>y) is formed over the surface of thesilicon oxide. It is to be noted that the semiconductor film is oxidizedby plasma treatment in an oxygen atmosphere (for example, an atmospherecontaining oxygen (O₂) and a rare gas (at least one of He, Ne, Ar, Kr,and Xe) or an atmosphere containing oxygen, hydrogen (H₂), and rare gas,or an atmosphere containing dinitrogen monoxide and a rare gas. On theother hand, a semiconductor film is nitrided by plasma treatment in anitrogen atmosphere (for example, an atmosphere containing nitrogen (N₂)and a rare gas (at least one of He, Ne, Ar, Kr, and Xe), an atmosphereincluding nitrogen, hydrogen, and a rare gas, or an atmospherecontaining NH₃ and a rare gas). As a rare gas, for example, Ar can beused. A gas in which Ar and Kr are mixed may be used as well.Accordingly, the insulating films 1521 a and 1521 b contain a rare gas(containing at least one of He, Ne, Ar, Kr, and Xe) used for the plasmatreatment. When Ar is used, the insulating films 1521 a and 1521 bcontain Ar.

In addition, the plasma treatment is conducted with an electron densityof 1×10¹¹ to 1×10¹³ cm⁻³ or more and an electron temperature of plasmaof 0.5 to 1.5 eV in the atmosphere containing the gas described above.The electron density of plasma is high and the electron temperaturearound an object (here, the semiconductor films 1503 a and 1503 b)formed over the substrate 1501 is low. Thus, plasma damages to theobject can be avoided. In addition, since the electron density of plasmais 1×10¹¹ cm⁻³ or higher, the oxide film or the nitride film formed byoxidizing or nitriding the object by the plasma treatment has a superiorevenness in film thickness as compared to a film formed by a CVD method,a sputtering method or the like, and thus, can be a dense film. Inaddition, since the electron temperature of plasma is 1 eV or lower, theoxidation treatment or the nitriding treatment can be conducted at alower temperature than conventional plasma treatment or a thermaloxidation method. For example, the oxidation treatment or the nitridingtreatment can be conducted sufficiently even when the plasma treatmentis conducted at a lower temperature by at least 100° C. than adistortion point of a glass substrate. As the frequency for producingplasma, a high frequency wave such as a micro wave (2.45 GHz) can beemployed. Hereinafter, the plasma treatment is performed with theaforementioned conditions unless specifically referred.

Next, the gate insulating film 1504 is formed to cover the insulatingfilms 1521 a and 1521 b (FIGS. 16C-1 and 16C-2). The gate insulatingfilm 1504 can be formed to have a single layer structure or a multilayerstructure of insulating films containing nitrogen or oxygen such assilicon oxide (SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride(SiO_(x)N_(y)) (x>y), or silicon nitride oxide (SiN_(x)O_(y)) (x>y) by aknown method (a sputtering method, an LPD method, a plasma CVD method,or the like). For example, when Si is used for the semiconductor films1503 a and 1503 b, and silicon is oxidized by the plasma treatment,silicon oxide is formed as the insulating films 1521 a and 1521 b overthe surfaces of the semiconductor films 1503 a and 1503 b. In this case,silicon oxide (SiO_(x)) is formed as the gate insulating film over theinsulating films 1521 a and 1521 b. In addition, when the thickness ismade thinner, in FIGS. 16B-1 and 16B-2, it is possible that theinsulating films 1521 a and 1521 b which are formed by oxidizing ornitriding the semiconductor films 1503 a and 1503 b by the plasmatreatment, are used as the gate insulating films.

Next, by forming the gate electrode 1505 or the like over the gateinsulating film 1504, a layer including a semiconductor element can beformed, which has an n-type thin film transistor 1510 a and a p-typethin film transistor 1510 b each using the island-shaped semiconductorfilms 1503 a and 1503 b as channel forming regions (FIGS. 16D-1 and16D-2).

Before forming the gate insulating film 1504 over the semiconductorfilms 1503 a and 1503 b, the surface of each of the semiconductor films1503 a and 1503 b is oxidized or nitrided by the plasma treatment. As aresult, a short-circuit or the like between the gate electrode and thesemiconductor film due to a coverage defect of the gate insulating film1504 in the end portions 1551 a, 1551 b of the channel forming regionscan be prevented. In other words, in the case where the angles of theend portions of the island-shaped semiconductor films are formed almostvertical (θ=85° to 100°, when the gate insulating film is formed tocover the semiconductor films by a CVD method, a sputtering method orthe like, there is a risk of a coverage defect due to breakage of thegate insulating film, or the like at the end portions of thesemiconductor films. However, when the plasma treatment is conducted tothe surface of the semiconductor film to oxide or nitride the surface,coverage defects and the like of the gate insulating film at the endportion of the semiconductor film can be prevented.

In FIGS. 16A to 16D, the gate insulating film 1504 may be oxidized ornitrided by conducting plasma treatment after forming the gateinsulating film 1504. In this case, the gate insulating film 1504 isformed to cover the semiconductor films 1503 a and 1503 b (FIGS. 17A-1and 17A-2), and plasma treatment is conducted to the gate insulatingfilm 1504 to oxidize or nitride the gate insulating film 1504, therebyforming an oxide film or a nitride film 1523 (hereinafter also referredto as an insulating film 1523) over the surface of the gate insulatingfilm 1504 (FIGS. 17B-1 and 17B-2). The conditions for the plasmatreatment can be similar to those of FIGS. 16B-1 and 16B-2. In addition,the insulating film 1523 contains a rare gas used in the plasmatreatment, for example, in the case of using Ar, Ar is contained in theinsulating film 1523.

In FIGS. 17B-1 and 17B-2, after the plasma treatment is conducted in anatmosphere containing oxygen to oxidize the gate insulating film 1504,plasma treatment may be conducted again in an atmosphere containingnitrogen to nitride the gate insulating film 1504. In this case, siliconoxide (SiO_(x)) or silicon oxynitride (SiO_(x)N_(y)) (x>y) is formedover the semiconductor films 1503 a and 1503 b, and silicon nitrideoxide (SiN_(x)O_(y)) (x>y) is formed in contact with the gate electrode1505. After that, the gate electrode 1505 is formed over the insulatingfilm 1523, and a layer including a semiconductor element can bemanufactured, which has the n-type thin film transistor 1510 a and thep-type thin film transistor 1510 b each using the island-shapedsemiconductor films 1503 a and 1503 h as the channel forming regions(FIGS. 17C-1 and 17C-2).

In this manner, by conducting the plasma treatment to the gateinsulating film, the surface of the gate insulating film is oxidized ornitrided to be enhanced in its film quality. Thus, a dense film can beobtained. The insulating film obtained by the plasma treatment is denserand has fewer defects such as pinholes as compared to an insulating filmformed by a CVD method or a sputtering method, and thus, thecharacteristics of a thin film transistor can be enhanced.

In FIGS. 17A to 17C, the case is described, where the plasma treatmentis conducted to the semiconductor films 1503 a and 1503 b in advance,and the surfaces of the semiconductor films 1503 a and 1503 b isoxidized or nitrided. However, a method may be employed, in which plasmatreatment is conducted after forming the gate insulating film 1504without conducting the plasma treatment to the semiconductor films 1503a and 1503 b. In this manner, by conducting the plasma treatment beforeforming the gate electrode, even when coverage defects due to breakageof the gate insulating film occurs at the end portions of thesemiconductor films, the semiconductor film exposed due to the coveragedefects can be oxidized or nitrided, and thus, a short-circuit betweenthe gate electrode and the semiconductor film caused by the coveragedefect of the gate insulating film at the end portions of thesemiconductor films, or the like can be prevented.

Even when the end portions of the island-shaped semiconductor films areformed almost vertical, the plasma treatment is conducted to thesemiconductor films or the gate insulating film to oxidize or nitridethe semiconductor films or the gate insulating film, thereby avoiding ashort-circuit between the gate electrode and the semiconductor filmscaused by coverage defects of the gate insulating film at the endportions of the semiconductor films.

Next, the case is described where the end portion of theisland-semiconductor film has a tapered shape (θ=30° to 85°) in theisland-shaped semiconductor film provided over the substrate.

The island-shaped semiconductor films 1503 a and 1503 b are formed overthe substrate 1501 (FIGS. 18A-1 and 18A-2). As to the island-shapedsemiconductor films 1503 a and 1503 b, an amorphous semiconductor filmis formed using a material mainly containing silicon (Si) (for example,Si_(x)Ge_(1-x), or the like) over an insulating film 1502 which havebeen formed over the substrate 1501, by a known method (a sputteringmethod, an LPCVD method, a plasma CVD method, or the like). Then, theamorphous semiconductor film is crystallized by a known crystallizationmethod such as a laser crystallization method, a thermal crystallizationmethod using RTA or an annealing furnace, a thermal crystallizationmethod using a metal element promoting crystallization. Then, thesemiconductor film is selectively etched and removed. In FIGS. 18A to18D, the end portions of the island-shaped semiconductor films 1503 aand 1503 b are tapered (θ=30° to 85°).

A gate insulating film 1504 is formed to cover the semiconductor films1503 a and 1503 b (FIGS. 18B-1 and 18B-2). The gate insulating film 1504can be formed to have a single layer structure or a multilayer structureof insulating films containing nitrogen or oxygen such as silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y))(x>y), or silicon nitride oxide (SiN_(x)O_(y)) (x>y) by a known method(such as a sputtering method, an LPCVD method, or a plasma CVD method).

Then, the gate insulating film 1504 is oxidized or nitrided by plasmatreatment, and thus, an oxide film or a nitride film 1524 (hereinafteralso referred to as an insulating film 1524) is formed over the surfaceof the gate insulating film 1504 (FIGS. 18C-1 and 18C-2). Note that theconditions for the plasma treatment can be similar to those describedabove. For example, when silicon oxide (SiO_(x)) or silicon oxynitride(SiO_(x)N_(y)) (x>y) is used as the gate insulating film 1504, plasmatreatment is conducted in an atmosphere containing oxygen to oxidize thegate insulating film 1504. The film obtained over the surface of thegate insulating film by the plasma treatment is dense and has fewerdefects such as pinholes as compared with a gate insulating film formedby a CVD method, a sputtering method or the like. On the other hand,plasma treatment is conducted in an atmosphere containing nitrogen tonitride the gate insulating film 1504, silicon nitride oxide(SiN_(x)O_(y)) (x>y) can be provided as the insulating film 1524 overthe surface of the gate insulating film 1504. In addition, after plasmatreatment is conducted in an atmosphere containing oxygen to oxidize thegate insulating film 1504, plasma treatment may be conducted again in anatmosphere containing nitrogen to nitride the gate insulating film 1504.In addition, the insulating film 1524 contains a rare gas used in theplasma treatment, for example, in the case of using Ar, Ar is containedin the insulating film 1524.

A layer including a semiconductor element can be manufactured, which hasan n-type thin film transistor 1510 a and a p-type thin film transistor1510 b each using the semiconductor films 1503 a and 1503 b as channelforming regions by forming the gate electrode 1505 and the like over thegate insulating film 1504 (FIGS. 18D-1 and 18D-2).

In this manner, by conducting the plasma treatment to the gateinsulating film, an insulating film formed of an oxide film or a nitridefilm is formed over the surface of the gate insulating film, and thesurface of the gate insulating film can be enhanced in its film quality.The oxidized or nitrided insulating film by the plasma treatment isdenser and has fewer defects such as pinholes as compared to a gateinsulating film formed by a CVD method or a sputtering method, and thus,the characteristics of a thin film transistor can be enhanced. Further,it is possible to prevent a short-circuit between the gate electrode andthe semiconductor film caused by the coverage defect of the gateinsulating film or the like at the end portion of the semiconductor filmby forming the end portion of the semiconductor film into a taperedshape. However, by conducting the plasma treatment after forming thegate insulating film, a short-circuit between the gate electrode and thesemiconductor film, or the like can further be prevented.

A manufacturing method of a semiconductor device which is different fromthat in FIGS. 18A to 18D is described with reference to the drawings.Specifically, the case is described where plasma treatment isselectively conducted to an end portion of a semiconductor film having atapered shape.

The island-shaped semiconductor films 1503 a and 1503 b are formed overthe substrate 1501 (FIGS. 19A-1 and 19A-2). As to the island-shapedsemiconductor films 1503 a and 1503 b, an amorphous semiconductor filmis formed using a material mainly containing silicon (Si) (e.g.,Si_(x)Ge_(1-x) etc.) over an insulating film 1502 which have been formedover the substrate 1501, by a known method (a sputtering method, anLPCVD method, a plasma CVD method, or the like). Then, the amorphoussemiconductor film is crystallized and the semiconductor film isselectively etched using resists 1525 a and 1525 b as masks. A knowncrystallization method such as a laser crystallization method, a thermalcrystallization method using RTA or an annealing furnace, a thermalcrystallization method using a metal element promoting crystallization,a combination of the methods or the like can be adopted to crystallizethe amorphous semiconductor film.

Next, before removing the resists 1525 a and 1525 b used for etching thesemiconductor film, plasma treatment is conducted to selectively oxidizeor nitride the end portions of the island-shaped semiconductor films1503 a and 1503 b. An oxide film or a nitride film 1526 (hereinafter,also referred to as an insulating film 1526) is formed at each endportion of the semiconductor films 1503 a and 1503 b (FIGS. 19B-1 and19B-2). The plasma treatment is conducted with the above describedconditions. In addition, the insulating film 1526 contains a rare gasused in the plasma treatment.

A gate insulating film 1504 is formed to cover the semiconductor films1503 a and 1503 b (FIGS. 19C-1 and 19C-2). The gate insulating film 1504can be formed similarly as described above.

A layer including a semiconductor element can be manufactured, which hasan n-type thin film transistor 1510 a and a p-type thin film transistor1510 b each using the island-shaped semiconductor films 1503 a and 1503b as channel forming regions by forming the gate electrode 1505 and thelike over the gate insulating film 1504 (FIGS. 19D-1 and 19D-2).

When the end portions of the semiconductor films 1503 a and 1503 b aretapered, the end portions 1552 a and 1552 b of the channel formingregions formed in a part of the semiconductor films 1503 a and 1503 bare also tapered. Thus, the thickness of the semiconductor film or thegate insulating film varies as compared to the center portion, and thereis a risk that the characteristics of a thin film transistor areaffected. Thus, by selectively oxidizing or nitriding the end portionsof the channel forming regions by the plasma treatment, an insulatingfilm is formed in the semiconductor film which becomes the end portionsof the channel forming region. Thus, the effect on the thin filmtransistor due to the end portions of the channel forming region can bereduced.

FIGS. 19A to 19D show the example in which the plasma treatment isconducted to only the end portions of the semiconductor films 1503 a and1503 b for oxidation or nitridation. Needless to say, the plasmatreatment can also be conducted to the gate insulating film 1504 foroxidation or nitridation as shown in FIGS. 18A to 18D (FIGS. 21A-1 and21A-2).

Next, a manufacturing method of a layer including a semiconductorelement is described with reference to the drawings. The method isdifferent from the method described above. Specifically, plasmatreatment is applied to a semiconductor film having a tapered shape.

Island-shaped semiconductor films 1503 a and 1503 b are formed over thesubstrate 1501 similarly as described above (FIGS. 20A-1 and 20A-2).

Next, plasma treatment is conducted to the semiconductor films 1503 aand 1503 b to oxidize or nitride the semiconductor films 1503 a and 1503b, oxide films or nitride films 1527 a and 1527 b (hereinafter, alsoreferred to as insulating films 1527 a, 1527 b) are formed (FIGS. 20B-1and 20B-2). The plasma treatment can be conducted with the abovedescribed conditions. For example, when Si is used for the semiconductorfilms 1503 a and 1503 b, silicon oxide (SiO_(x)) or silicon nitride(SiN_(x)) is formed as the insulating films 1527 a and 1527 b. Inaddition, after oxidizing the semiconductor films 1503 a and 1503 b byplasma treatment, plasma treatment may be conducted again to nitride thesemiconductor films 1503 a and 1503 b. In this case, silicon oxide(SiO_(x)) or silicon oxynitride (SiO_(x)N_(y)) (x>y) is formed incontact with the semiconductor films 1503 a and 1503 b, and siliconnitride oxide (SiN_(x)O_(y)) (x>y) is formed over the surface of thesilicon oxide. In addition, the insulating films 1527 a and 1527 bcontain a rare gas used for the plasma treatment. By the plasmatreatment, the end portions of the semiconductor films 1503 a and 1503 bare oxidized or nitrided at the same time.

Next, a gate insulating film 1504 is formed to cover the insulatingfilms 1527 a and 1527 b (FIGS. 20C-1 and 20C-2). As the gate insulatingfilm 1504, a single layer structure or a stacked-layer structure ofinsulating films containing nitrogen or oxygen such as silicon oxide(SiO_(x)), silicon nitride (SiN_(x)), silicon oxynitride (SiO_(x)N_(y))(x>y), or silicon nitride oxide (SiN_(x)O_(y)) (x>y) can be employed bya known method (a sputtering method, an LPCVD method, a plasma CVDmethod, or the like). For example, in the case where the semiconductorfilms 1503 a and 1503 b using Si are oxidized by plasma treatment toform silicon oxide as the insulating films 1527 a and 1527 b over thesurface of the semiconductor films 1503 a and 1503 b, silicon oxide(SiO_(x)) is formed as the gate insulating film 1504 over the insulatingfilm 1527 a and 1527 b.

Next, a gate electrode 1505 or the like is formed over the gateinsulating film 1504, and a layer including a semiconductor element canbe manufactured, which has an n-type thin film transistor 1510 a and ap-type thin film transistor 1510 h each using the island-shapedsemiconductor films 1503 a and 1503 b as channel forming regions byforming the gate electrode 1505 and the like over the gate insulatingfilm 1504 (FIGS. 20D-1 and 20D-2).

When the end portions of the semiconductor films 1503 a and 1503 b aretapered, the end portions 1553 a and 1553 b of the channel formingregions formed in a portion of the semiconductor films 1503 a and 1503 bare also tapered. Thus, there is a risk that the characteristics of asemiconductor element are affected. By oxidizing or nitriding the endportions of the channel forming regions as a result of oxidizing ornitriding the semiconductor films by the plasma treatment, the effect ona semiconductor element can be reduced.

In FIGS. 20A to 20D, the example is shown in which only thesemiconductor films 1503 a and 1503 b are subjected to oxidization ornitridation by plasma treatment; however, the plasma treatment can beconducted to the gate insulating film 1504 for oxidation or nitridationas shown in FIGS. 18A to 18D (FIGS. 21B-1 and 21B-2). In this case,after the plasma treatment is conducted in an atmosphere containingoxygen to oxide the gate insulating film 1504, plasma treatment may beconducted again in an atmosphere containing nitrogen to nitride the gateinsulating film 1504. In this case, silicon oxide (SiO_(x)) or siliconoxynitride (SiO_(x)N_(y)) (x>y) is formed in the semiconductor films1503 a and 1503 b, and silicon nitride oxide (SiN_(x)O_(y)) (x>y) isformed in contact with the gate electrode 1505.

By conducting the plasma treatment in this manner, impurities such asdusts attached to the semiconductor film or the insulating film can beeasily removed. In general, in some cases, dusts (also referred to asparticles) are attached to the film formed by a CVD method, a sputteringmethod or the like. For example, as shown in FIG. 22A, a dust 1573 isformed over an insulating film 1572 formed by a CVD method, a sputteringmethod, or the like, which is formed over a film 1571 such as aninsulating film, a conductive film, or a semiconductor film, or thelike. In such a case, the insulating film 1572 is oxidized or nitridedby the plasma treatment and an oxide film or a nitride film 1574(hereinafter, also referred to as an insulating film 1574) is formedover the surface of the insulating film 1572. As to the insulating film1574, a portion under the dust 1573 as well as a portion in which thedust 1573 does not exist are oxidized or nitrided, and thus the volumeof the insulating film 1574 is increased. The surface of the dust 1573is also oxidized or nitrided by the plasma treatment to form aninsulating film 1575, and as a result, the volume of the dust 1573 isalso increased (FIG. 22B).

At this time, the dust 1573 can be easily removed from the surface ofthe insulating film 1574 by simple cleaning such as brush cleaning. Inthis manner, by the plasma treatment, even a minute dust attached to theinsulating film or a semiconductor film can be removed easily. It isnoted that this is an effect obtained by conducting the plasmatreatment, and this is true to other embodiment modes as well as thisembodiment mode.

As described above, by improving the film quality of the surface of thesemiconductor film or the gate insulating film by oxidation ornitridation by the plasma treatment, a dense insulating film having goodfilm quality can be formed. In addition, dusts etc., attached to thesurface of the insulating film can be removed easily by cleaning.Consequently, even when the insulating film is formed thinner, defectssuch as pinholes can be avoided, and miniaturization and higherperformance of a semiconductor element such as a thin film transistorcan be realized.

It is to be noted that this embodiment can be freely implemented incombination with the aforementioned embodiment modes.

This application is based on Japanese Patent Application serial no.2005-129326 filed on Apr. 27, 2005, in Japan Patent Office, the entirecontents of which are hereby incorporated by reference.

What is claimed is:
 1. A semiconductor device comprising: a conductivelayer serving as an antenna; and a semiconductor element electricallyconnected to the conductive layer, wherein the conductive layer has afirst region, a second region and a third region between the firstregion and the second region, wherein the conductive layer is bent sothat a surface of the first region is parallel to a normal direction ofthe third region, and a surface of the second region is parallel to thenormal direction of the third region, and wherein at least a part of thesemiconductor element is surrounded by the first region, the secondregion and the third region.
 2. The semiconductor device according toclaim 1, wherein the conductive layer comprises at least one selectedfrom the group consisting of gold, silver, copper, palladium, platinumand aluminum.
 3. The semiconductor device according to claim 1 furthercomprises an insulator surrounded by the first region, the second regionand the third region.
 4. The semiconductor device according to claim 3,wherein the semiconductor element is surrounded by the insulator.
 5. Asemiconductor device comprising: a first conductive layer; a secondconductive layer; a third conductive layer, wherein the first conductivelayer, the second conductive layer and the third conductive layer serveas an antenna; and a semiconductor element electrically connected to atleast one of the first conductive layer, the second conductive layer andthe third conductive layer, wherein the first conductive layer has afirst region, a second region and a third region between the firstregion and the second region, wherein the first conductive layer is bentso that a surface of the first region is parallel to a normal directionof the third region, and a surface of the second region is parallel tothe normal direction of the third region, wherein at least a part of thesecond conductive layer is aligned with the first region of the firstconductive layer, wherein at least a part of the third conductive layeris aligned with the second region of the first conductive layer, andwherein at least a part of the semiconductor element is surrounded bythe first region, the second region and the third region.
 6. Thesemiconductor device according to claim 5, wherein at least one of thefirst conductive layer, the second conductive layer and the thirdconductive layer comprises at least one selected from the groupconsisting of gold, silver, copper, palladium, platinum and aluminum. 7.The semiconductor device according to claim 5 further comprises aninsulator surrounded by the first region, the second region and thethird region.
 8. The semiconductor device according to claim 7, whereinthe semiconductor element is surrounded by the insulator.
 9. Asemiconductor device comprising: a conductive layer serving as anantenna; and a semiconductor element electrically connected to theconductive layer, wherein the conductive layer has a first region, asecond region and a third region between the first region and the secondregion, wherein the conductive layer is bent so that a surface of thefirst region is parallel to a normal direction of the third region, anda surface of the second region is parallel to the normal direction ofthe third region, wherein the semiconductor element includes atransistor and a memory portion, and wherein at least a part of thesemiconductor element is surrounded by the first region, the secondregion and the third region.
 10. The semiconductor device according toclaim 9, wherein the semiconductor element further comprises a powersource circuit portion.
 11. The semiconductor device according to claim9, wherein the transistor includes a gate electrode and a sidewall on aside surface of the gate electrode.
 12. The semiconductor deviceaccording to claim 9, wherein the conductive layer comprises at leastone selected from the group consisting of gold, silver, copper,palladium, platinum and aluminum.
 13. The semiconductor device accordingto claim 9 further comprises an insulator surrounded by the firstregion, the second region and the third region.
 14. The semiconductordevice according to claim 13, wherein the semiconductor element issurrounded by the insulator.